Case-sensitivity of identifiers

Case-sensitivity of identifiers
You are encouraged to solve this task according to the task description, using any language you may know.

Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:

The three dogs are named Benjamin, Samba and Bernie.

For a language that is lettercase insensitive, we get the following output:

There is just one dog named Bernie.

Related task

• Unicode variable names

11l

11l identifiers are case sensitive.

V dog = ‘Benjamin’
V Dog = ‘Samba’
V DOG = ‘Bernie’
print(‘The three dogs are named ’dog‘, ’Dog‘ and ’DOG‘.’)

Action!

PROC Main()
  CHAR ARRAY dog="Bernie"

  PrintF("There is just one dog named %S.",dog)
RETURN

Output:

Screenshot from Atari 8-bit computer

There is just one dog named Bernie.

Ada

case insensitive

with Ada.Text_IO;
procedure Dogs is
   Dog : String := "Bernie";
begin
   Ada.Text_IO.Put_Line ("There is just one dog named " & DOG);
end Dogs;

Output:

There is just one dog named Bernie

Agena

Translation of Algol W. Agena is case sensitive, as this example demonstrates. Tested with Agena 2.9.5 Win32

scope
    local dog := "Benjamin";
    scope
        local Dog := "Samba";
        scope
            local DOG := "Bernie";
            if DOG <> Dog or DOG <> dog
            then print( "The three dogs are named: " & dog & ", " & Dog & " and " & DOG )
            else print( "There is just one dog named: " & DOG )
            fi
        epocs
    epocs
epocs

Output:

The three dogs are named: Benjamin, Samba and Bernie

Aime

text dog, Dog, DOG;

dog = "Benjamin";
Dog = "Samba";
DOG = "Bernie";

o_form("The three dogs are named ~, ~ and ~.\n", dog, Dog, DOG);

ALGOL 68

Works with: ALGOL 68 version Revision 1.

Works with: ALGOL 68G version Any - tested with release algol68g-2.6.

A joke code entry... :-) ¢ but the code does actually work!

File: Case-sensitivity_of_identifiers.a68

#!/usr/bin/a68g --script #
# -*- coding: utf-8 -*- #

STRING dog = "Benjamin";
OP D = (INT og)STRING: "Samba"; 
OP DOG = (INT gy)STRING: "Bernie";
INT og=~, gy=~;
 
main:(
  printf(($"The three dogs are named "g", "g" and "g"."l$, dog, Dog, DOGgy));
  0
)

Output:

The three dogs are named Benjamin, Samba and Bernie.

Alternative version.

Works with: Rutgers_ALGOL_68 version Any - Tested with the DOS version

Translation of: Algol W

Most recent implementations of Algol 68 use "upper stropping", the "keywords" are in upper case and the identifiers are an lower case. This precludes use of e.g. Dog or DOG as the name of a variable or constant.
However, depending on the "stropping" convention used and the implementation, Algol 68 can be case-sensitive. Rutgers ALGOL 68 uses quote stropping and allows both upper and lower case in identifiers and bold words. The standard bold words must be in lower-case.

'begin'
    'string' dog = "Benjamin";
    'begin'
        'string' Dog = "Samba";
        'begin'
            'string' DOG = "Bernie";
            'if' DOG /= Dog 'or' DOG /= dog
            'then' print( ( "The three dogs are named: ", dog, ", ", Dog, " and ", DOG ) )
            'else' print( ( "There is just one dog named: ", DOG ) )
            'fi'
        'end'
    'end'
'end'

Output:

The three dogs are named: Benjamin, Samba and Bernie

ALGOL W

Algol W identifiers are not case-sensitive but variable names in inner blocks can be the same as those in outer blocks...

begin
    string(8) dog;
    dog := "Benjamin";
    begin
        string(8) Dog;
        Dog := "Samba";
        begin
            string(8) DOG;
            DOG := "Bernie";
            if DOG not = Dog
            or DOG not = dog
            then write( "The three dogs are named: ", dog, ", ", Dog, " and ", DOG )
            else write( "There is just one dog named: ", DOG )
        end
    end
end.

Output:

There is just one dog named: Bernie  

APL

      DOG←'Benjamin'
      Dog←'Samba'
      dog←'Bernie'
      'The three dogs are named ',DOG,', ',Dog,', and ',dog
The three dogs are named Benjamin, Samba, and Bernie

AppleScript

AppleScript labels are case insensitive, every instance of a particular label within a script document compiling to the same case as the first instance. It's possible to use vertical bars — normally used to distinguish labels from identical language or library keywords — to give the same label different cases within a script, but there's little point in doing so as it's still the same label.

set {dog, |Dog|, |DOG|} to {"Benjamin", "Samba", "Bernie"}

if (dog = |Dog|) then
    if (dog = |DOG|) then return "There is just one dog named " & dog & "."
    return "There are two dogs named " & dog & " and " & |DOG| & "."
else if (dog = |DOG|) then
    return "There are two dogs named " & dog & " and " & |Dog| & "."
end if
return "The three dogs are named " & dog & ", " & |Dog| & ", and " & |DOG| & "."

Output:

"There is just one dog named Bernie."

Arturo

dog: "Benjamin"
Dog: "Samba"
DOG: "Bernie"

dogs: @[dog Dog DOG]

print ["The" size dogs "dog(s) are named" join.with:", " dogs]

Output:

The 3 dog(s) are named Benjamin, Samba, Bernie

AutoHotkey

dog := "Benjamin"
Dog := "Samba"
DOG := "Bernie"
MsgBox There is just one dog named %dOG%

AWK

BEGIN {
	dog = "Benjamin"
	Dog = "Samba"
	DOG = "Bernie"
	printf "The three dogs are named %s, %s and %s.\n", dog, Dog, DOG
}

The three dogs are named Benjamin, Samba and Bernie.

BASIC

Applesoft BASIC

Applesoft BASIC is case-insensitive. Applesoft BASIC keyword tokens and variable names get converted to upper case in programs. Only the first two characters of variable names are significant.

dog$ = "Benjamin":Dog$ = "Samba":DOG$ = "Bernie":III = 254 * (DOG$ = dog$ AND Dog$ = DOG$) + 1: PRINT  MID$ ("There is just one dog",256 - III) MID$ ("The three dogs are",III)" named " MID$ (dog$ + ", " + Dog$ + " and ",III)DOG$"."

Output:

There is just one dog named Bernie.

The Apple II and Apple II plus will convert all input characters to upper case.

THERE IS JUST ONE DOG NAMED BERNIE.

BASIC256

BASIC256 is case-insensitive

dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
print "There is just one dog, named "; dog
end

Output:

There is just one dog, named Bernie

BBC BASIC

      dog$ = "Benjamin"
      Dog$ = "Samba"
      DOG$ = "Bernie"
      PRINT "The three dogs are " dog$ ", " Dog$ " and " DOG$ "."

Output:

The three dogs are Benjamin, Samba and Bernie.

Chipmunk Basic

Chipmunk Basic is case-insensitive

10 dog$ = "Benjamin"
20 dog$ = "Smokey"
30 dog$ = "Samba"
40 dog$ = "Bernie"
50 print "There is just one dog, named ";dog$

Output:

There is just one dog, named Bernie

FreeBASIC

' FB 1.05.0 Win64

' FreeBASIC is case-insensitive
Dim dog As String 
dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
Print "There is just one dog, named "; dog
Sleep

Output:

There is just one dog, named Bernie

FutureBasic

FB is lettercase-insensitive and throws an error with variables or constants with identical names but of varying case. However, here's an easy work around.

CFDictionaryRef canines
canines = @{@"dog":@"Benjamin", @"Dog":@"Samba", @"DOG":@"Bernie"}
print "The three dogs are "; canines[@"dog"]; ", "; canines[@"Dog"]; " and "; canines[@"DOG"]; "."

HandleEvents

Output:

There are three dogs named Benjamin, Samba and Bernie.

GW-BASIC

Works with: PC-BASIC version any

GW-BASIC is case-insensitive. GW-BASIC keyword tokens and variable names get converted to upper case in programs.

10 dog$ = "Benjamin"
20 dog$ = "Smokey"
30 dog$ = "Samba"
40 dog$ = "Bernie"
50 print "There is just one dog, named ";dog$

Output:

There is just one dog, named Bernie

Liberty BASIC

Works with: Just BASIC

Just BASIC and Liberty BASIC names are case sensitive

NB the IDE warns you that there are similar variables named dog$, Dog$ & DOG$

dog$ = "Benjamin"
Dog$ = "Samba"
DOG$ = "Bernie"
print "The three dogs are "; dog$; ", "; Dog$; " and "; DOG$; "."

end

Output:

The three dogs are Benjamin, Samba and Bernie.

Minimal BASIC

Minimal BASIC is case-insensitive. Minimal BASIC convert all input characters to upper case.

10 let d$ = "Benjamin"
20 let D$ = "Samba"
30 print "There is just one dog, named "; d$
40 end

Output:

THERE IS JUST ONE DOG, NAMED SAMBA

MSX Basic

Works with: MSX BASIC version any

MSX BASIC is case-insensitive. MSX-BASIC keyword tokens and variable names get converted to upper case in programs.

10 dog$ = "Benjamin"
20 dog$ = "Smokey"
30 dog$ = "Samba"
40 dog$ = "Bernie"
50 print "There is just one dog, named ";dog$

Output:

There is just one dog, named Bernie

PureBasic

dog$="Benjamin"
Dog$="Samba"
DOG$="Bernie"
Debug "There is just one dog named "+dog$

QBasic

QBASIC is case-insensitive

DOG$ = "Benjamin"
DOG$ = "Samba"
DOG$ = "Bernie"
PRINT "There is just one dog, named "; DOG$

Quite BASIC

Quite BASIC is case-insensitive

10 let d$ = "Benjamin"
20 let D$ = "Samba"
30 print "There is just one dog, named "; d$
40 end

Output:

There is just one dog, named Samba

Run BASIC

Works with: Just BASIC

Works with: Liberty BASIC

Run BASIC names are case sensitive

dog$ = "Benjamin"
doG$ = "Smokey"
Dog$ = "Samba"
DOG$ = "Bernie"
print "The 4 dogs are "; dog$; ", "; doG$; ", "; Dog$; " and "; DOG$; "."

Output:

The 4 dogs are Benjamin, Smokey, Samba and Bernie.

True BASIC

Works with: QBasic

True Basic is case-insensitive

LET dog$ = "Benjamin"
LET Dog$ = "Samba"
LET DOG$ = "Bernie"
PRINT "There is just one dog, named "; dog$
END

XBasic

XBasic in case-insensitive

PROGRAM	"Case-sensitivity"
VERSION	"0.0000"

DECLARE FUNCTION  Entry ()

FUNCTION  Entry ()
  dog$ = "Benjamin"
  dog$ = "Smokey"
  dog$ = "Samba"
  dog$ = "Bernie"
  
  PRINT "There is just one dog, named "; dog$
END FUNCTION
END PROGRAM

Output:

There is just one dog, named Bernie

Yabasic

Yabasic names are case sensitive:

dog$ = "Benjamin"
doG$ = "Smokey"
Dog$ = "Samba"
DOG$ = "Bernie"
print "The four dogs are named ", dog$, ", ", doG$, ", ", Dog$, " and ", DOG$
end

Output:

The four dogs are named Benjamin, Smokey, Samba and Bernie

ZX Spectrum Basic

10 LET D$="Benjamin"
20 PRINT "There is just one dog named ";d$

Batch File

@echo off

set dog=Benjamin
set Dog=Samba
set DOG=Bernie

echo There is just one dog named %dog%.
pause>nul

Output:

There is just one dog named Bernie.

bc

The only variables are 'a' through 'z'. They can only hold numbers, not strings. Some implementations allow longer names like 'dog', but only with lowercase letters. A name like 'Dog' or 'DOG' is a syntax error.

obase = 16
ibase = 16

/*
 * Store the hexadecimal number 'BE27A312'
 * in the variable 'd'.
 */
d = BE27A312
"There is just one dog named "; d
quit

There is just one dog named BE27A312

Bracmat

( Benjamin:?dog
& Samba:?Dog
& Bernie:?DOG
& out$("There are three dogs:" !dog !Dog and !DOG)
);

Output:

There are three dogs: Benjamin Samba and Bernie

Brlcad

The three dogs are drawn as spheres in this simple example:

opendb dogs.g y            # Create a database to hold our dogs
units ft                   # The dogs are measured in feet
in dog.s sph 0 0 0 1       # Benjie is a little Scottie dog
in Dog.s sph 4 0 0 3       # Samba is a Labrador
in DOG.s sph 13 0 0 5      # Bernie is massive. He is a New Foundland
echo The three dogs are named Benjamin, Samba and Bernie

C

C is case sensitive; if it would be case insensitive, an error about redefinition of a variable would be raised.

#include <stdio.h>

static const char *dog = "Benjamin";
static const char *Dog = "Samba";
static const char *DOG = "Bernie";

int main()
{
    printf("The three dogs are named %s, %s and %s.\n", dog, Dog, DOG);
    return 0;
}

C#

C# is case sensitive

using System;

class Program
{
    static void Main(string[] args)
    {
        string dog = "Benjamin";
        string Dog = "Samba";
        string DOG = "Bernie";
        Console.WriteLine(string.Format("The three dogs are named {0}, {1}, and {2}.", dog, Dog, DOG));
    }
}

C++

C++ is case-sensitive.

#include <iostream>
#include <string>
using namespace std;

int main() {
    string dog = "Benjamin", Dog = "Samba", DOG = "Bernie";
    
    cout << "The three dogs are named " << dog << ", " << Dog << ", and " << DOG << endl;
}

Output:

The three dogs are named Benjamin, Samba, and Bernie

Clojure

user=> (let [dog "Benjamin" Dog "Samba" DOG "Bernie"] (format "The three dogs are named %s, %s and %s." dog Dog DOG))
"The three dogs are named Benjamin, Samba and Bernie."

COBOL

* Case sensitivity of identifiers
       *>* Commented-out lines in the working storage
       *>* are considered as invalid redefinitions
       *>* of ''dog'' that can only be ambiguously
       *>* referenced in the procedure body.

       IDENTIFICATION DIVISION.
       PROGRAM-ID. case-sensitivity.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       *>* 01  dog PICTURE X(8) VALUE IS "Benjamin".
       *>* 01  Dog PICTURE X(5) VALUE IS "Samba".
       01  DOG PICTURE X(6) VALUE IS "Bernie".
       PROCEDURE DIVISION.
         DISPLAY
       *>*     "The three dogs are named "
       *>*     dog ", " Dog " and " DOG "."
           "There is just one dog named " DOG "."
         END-DISPLAY
         STOP RUN.
       END PROGRAM case-sensitivity.

CoffeeScript

dog="Benjamin"
Dog = "Samba"
DOG = "Bernie"
console.log "The three dogs are names #{dog}, #{Dog}, and #{DOG}."

output

> coffee foo.coffee 
The three dogs are names Benjamin, Samba, and Bernie.

Common Lisp

CL-USER> (let* ((dog "Benjamin") (Dog "Samba") (DOG "Bernie"))
	   (format nil "There is just one dog named ~a." dog))
; in: LAMBDA NIL
;     (LET* ((DOG "Benjamin") (DOG "Samba") (DOG "Bernie"))
;       (FORMAT NIL "There is just one dog named ~a." DOG))
; 
; caught STYLE-WARNING:
;   The variable DOG is defined but never used.
; 
; caught STYLE-WARNING:
;   The variable DOG is defined but never used.
; 
; compilation unit finished
;   caught 2 STYLE-WARNING conditions
"There is just one dog named Bernie."

These are the style warnings from SBCL. Other implementations of Common Lisp might give different warnings.

Cowgol

include "cowgol.coh";

var dog := "Benjamin";
var Dog := "Samba";
var DOG := "Bernie";

print("There are three dogs named ");
print(dog);
print(", ");
print(Dog);
print(", and ");
print(DOG);
print(".\n");

Output:

There are three dogs named Benjamin, Samba, and Bernie.

Crystal

dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"

puts "The three dogs are named #{dog}, #{Dog} and #{DOG}."

Note that in Crystal, variables with all-caps identifiers (like DOG) are always constants.

Output:

The three dogs are named Benjamin, Samba and Bernie.

D

import std.stdio;

void main() {
    string dog = "Benjamin";
    // identifiers that start with capital letters are type names
    string Dog = "Samba";
    string DOG = "Bernie";
    writefln("There are three dogs named ",
             dog, ", ", Dog, ", and ", DOG, "'");
}

Output:

There are three dogs named Benjamin, Samba, and Bernie'

Dart

Dart names are case sensitive

note: The name of the variables 'Dog' and 'DOG' is not a lowerCamelCase identifier.

void main() {
  String dog = "Benjamin", doG = "Smokey", Dog = "Samba", DOG = "Bernie";

  print("The four dogs are named $dog, $doG, $Dog and $DOG");
}

Output:

The four dogs are named Benjamin, Smokey, Samba and Bernie

dc

A register name has only one character, so this example uses 'd' and 'D'.

[Benjamin]sd
[Samba]sD
[The two dogs are named ]P ldP [ and ]P lDP [.
]P

Output:

The two dogs are named Benjamin and Samba.

Delphi

Delphi is case insensitive.

program CaseSensitiveIdentifiers;

{$APPTYPE CONSOLE}

var
  dog: string;
begin
  dog := 'Benjamin';
  Dog := 'Samba';
  DOG := 'Bernie';
  Writeln('There is just one dog named ' + dog);
end.

Output:

There is just one dog named Bernie

DWScript

var dog : String;

dog := 'Benjamin';
Dog := 'Samba';
DOG := 'Bernie';

PrintLn('There is just one dog named ' + dog);

Output:

There is just one dog named Bernie

Déjà Vu

local :dog "Benjamin"
local :Dog "Samba"
local :DOG "Bernie"
 
!print( "There are three dogs named " dog ", " Dog " and " DOG "." )

Output:

There are three dogs named Benjamin, Samba and Bernie.

Draco

proc main() void:
    *char dog = "Benjamin",
          Dog = "Samba",
          DOG = "Bernie";

    writeln("There are three dogs named ",
            dog, ", ", Dog, ", and ", DOG, ".")
corp

Output:

There are three dogs named Benjamin, Samba, and Bernie.

EasyLang

EasyLang is case-sensitive.

dog$ = "Benjamin"
Dog$ = "Samba"
DOG$ = "Bernie"
# 
print "The three dogs are named " & dog$ & ", " & Dog$ & ", and " & DOG$ & "."

EchoLisp

(define dog "Benjamin")
(define Dog "Samba")
(define DOG "Bernie")

(printf "The three dogs are named %a, %a and %a. " dog Dog DOG)
    The three dogs are named Benjamin, Samba and Bernie.

Ecstasy

String dog = "Benjamin"; // convention: lower camelCase for variable and property names
String Dog = "Samba";    // convention: upper CamelCase for class, type, and constant names
String DOG = "Bernie";   // convention: all-caps only for constants

@Inject Console console;
console.print($"There are three dogs named {dog}, {Dog}, and {DOG}");

Elena

In ELENA identifiers are case sensitive. ELENA 4.x:

import extensions;

public program()
{
    var dog := "Benjamin";
    var Dog := "Samba";
    var DOG := "Bernie";
    console.printLineFormatted("The three dogs are named {0}, {1} and {2}", dog, Dog, DOG)
}

Output:

The three dogs are named Benjamin, Samba and Bernie

Elixir

While Elixir's identifiers are case-sensitive, they generally must start with a lowercase letter. Capitalized identifiers are reserved for modules.

dog = "Benjamin"
doG = "Samba"
dOG = "Bernie"
IO.puts "The three dogs are named #{dog}, #{doG} and #{dOG}."

Output:

The three dogs are named Benjamin, Samba and Bernie.

Erlang

Erlang variables are case sensitive but must start with an uppercase letter.

-module( case_sensitivity_of_identifiers ).

-export( [task/0] ).

task() ->
	catch dog = "Benjamin", % Function will crash without catch
	Dog = "Samba",
	DOG = "Bernie",
	io:fwrite( "The three dogs are named ~s, ~s and ~s~n", [dog, Dog, DOG] ).

Output:

4> case_sensitivity_of_identifiers:task().
The three dogs are named dog, Samba and Bernie

Euphoria

Works with: Euphoria version 4.0.0

-- These variables are all different
sequence dog = "Benjamin"
sequence Dog = "Samba"
sequence DOG = "Bernie"
printf( 1, "The three dogs are named %s, %s and %s\n", {dog, Dog, DOG} )

F#

F# is case-sensitive.

let dog = "Benjamin"
let Dog = "Samba"
let DOG = "Bernie"
printfn "There are three dogs named %s, %s and %s" dog Dog DOG

Factor

Factor identifiers are case-sensitive.

USING: formatting locals ;
IN: scratchpad
[let
    "Benjamin" :> dog
    "Samba"    :> Dog
    "Bernie"   :> DOG
    { dog Dog DOG } "There are three dogs named %s, %s, and %s." vprintf
]

Output:

There are three dogs named Benjamin, Samba, and Bernie.

Forth

: DOG ." Benjamin" ;
: Dog ." Samba" ;
: dog ." Bernie" ;
: HOWMANYDOGS ." There is just one dog named " DOG ;
HOWMANYDOGS

Output:

There is just one dog named Bernie

Fortran

Works with: Fortran version 90 and later

Fortran is case insensitive, and so the three "dog" variants name the same variable - which therefore is multiply declared and will likely evoke a compiler complaint.

program Example
  implicit none

  character(8) :: dog, Dog, DOG

  dog = "Benjamin"
  Dog = "Samba"
  DOG = "Bernie"

  if (dog == DOG) then
    write(*,*) "There is just one dog named ", dog
  else
    write(*,*) "The three dogs are named ", dog, Dog, " and ", DOG
  end if

end program Example

Output:

 There is just one dog named Bernie

Frink

Frink is case-sensitive.

dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
println["There are three dogs named $dog, $Dog and $DOG"]

Gambas

Click this link to run this code

Gambas in case insensitive

Public Sub Main()
Dim dog As String 

Dog = "Benjamin"
DOG = "Samba"
dog = "Bernie"
Print "There is just one dog, named "; dog

End

Output:

There is just one dog, named Bernie

GAP

# GAP is case sensitive
ThreeDogs := function()
	local dog, Dog, DOG;
	dog := "Benjamin";
	Dog := "Samba";
	DOG := "Bernie";
	if dog = DOG then
		Print("There is just one dog named ", dog, "\n");
	else
		Print("The three dogs are named ", dog, ", ", Dog, " and ", DOG, "\n");
	fi;
end;

ThreeDogs();
# The three dogs are named Benjamin, Samba and Bernie

Go

Go is case sensitive. Further, visibility depends on case. See the Go entry under the Scope modifiers task.

package dogs

import "fmt"

// Three variables, three different names.
// (It wouldn't compile if the compiler saw the variable names as the same.)
var dog = "Salt"
var Dog = "Pepper"
var DOG = "Mustard"

func PackageSees() map[*string]int {
    // Print dogs visible from here.
    fmt.Println("Package sees:", dog, Dog, DOG)
    // Return addresses of the variables visible from here.
    // The point of putting them in a map is that maps store only
    // unique keys, so it will end up with three items only if
    // the variables really represent different places in memory.
    return map[*string]int{&dog: 1, &Dog: 1, &DOG: 1}
}

package main

import (
    . "dogs"
    "fmt"
)

func main() {
    // with the dogs package imported, there are three dogs.
    d := PackageSees()
    fmt.Println("There are", len(d), "dogs.\n")

    // Declaration of new variable dog.  It lives in this package, main.
    dog := "Benjamin"
    d = PackageSees()
    fmt.Println("Main sees:   ", dog, Dog, DOG)
    // Four dogs now.  two of the three visible from here are the
    // the same as ones in the dogs package.
    d[&dog] = 1
    d[&Dog] = 1
    d[&DOG] = 1
    fmt.Println("There are", len(d), "dogs.\n")

    // Not a declaration, just an assigment.  This assigns a new value to
    // the variable Dog declared in the package.  Dog is visible because
    // it begins with an upper case letter.
    Dog = "Samba"
    // same four dogs, same three visible, one just has a new name.
    d = PackageSees()
    fmt.Println("Main sees:   ", dog, Dog, DOG)
    d[&dog] = 1
    d[&Dog] = 1
    d[&DOG] = 1
    fmt.Println("There are", len(d), "dogs.\n")

    // Of course you can still declare a variable if you want to.  This
    // declares a new variable, shadowing DOG in the package and rendering
    // it inaccessable even though it begins with an upper case letter.
    var DOG = "Bernie"
    // five dogs now.  three visible from here.
    d = PackageSees()
    fmt.Println("Main sees:   ", dog, Dog, DOG)
    d[&dog] = 1
    d[&Dog] = 1
    d[&DOG] = 1
    fmt.Println("There are", len(d), "dogs.")
}

Output:

Package sees: Salt Pepper Mustard
There are 3 dogs.

Package sees: Salt Pepper Mustard
Main sees:    Benjamin Pepper Mustard
There are 4 dogs.

Package sees: Salt Samba Mustard
Main sees:    Benjamin Samba Mustard
There are 4 dogs.

Package sees: Salt Samba Mustard
Main sees:    Benjamin Samba Bernie
There are 5 dogs.

Groovy

Solution:

def dog = "Benjamin", Dog = "Samba", DOG = "Bernie"
println (dog == DOG ? "There is one dog named ${dog}" : "There are three dogs named ${dog}, ${Dog} and ${DOG}.")

Output:

There are three dogs named Benjamin, Samba and Bernie.

Haskell

Identifiers are case sensitive in Haskell, but must start with a lower case letter.

import Text.Printf

main = printf "The three dogs are named %s, %s and %s.\n" dog dOG dOg
    where dog = "Benjamin"
          dOG = "Samba"
          dOg = "Bernie"

Icon and Unicon

The program below demonstrates the three dog task. All variants of Icon/Unicon have case sensitive variable names. But if one wasn't this would find it.

procedure main()

   dog := "Benjamin"
   Dog := "Samba"
   DOG := "Bernie"
	
   if dog == DOG then 
      write("There is just one dog named ", dog,".") 
   else 
      write("The three dogs are named ", dog, ", ", Dog, " and ", DOG, ".")

end

J

   NB. These variables are all different
   dog=: 'Benjamin'
   Dog=: 'Samba'
   DOG=: 'Bernie'
   'The three dogs are named ',dog,', ',Dog,', and ',DOG
The three dogs are named Benjamin, Samba, and Bernie

Java

String dog = "Benjamin";
String Dog = "Samba"; //in general, identifiers that start with capital letters are class names
String DOG = "Bernie"; //in general, identifiers in all caps are constants
//the conventions listed in comments here are not enforced by the language
System.out.println("There are three dogs named " + dog + ", " + Dog + ", and " + DOG + "'");

JavaScript

Javascript is case sensitive.

var dog = "Benjamin";
var Dog = "Samba";
var DOG = "Bernie";
document.write("The three dogs are named " + dog + ", " + Dog + ", and " + DOG + ".");

jq

jq identifiers are case-sensitive.

Function parameters:

def task(dog; Dog; DOG):
 "The three dogs are named \(dog), \(Dog), and \(DOG)." ;

task("Benjamin"; "Samba"; "Bernie")

Output:

$ jq -n -f Case-sensitivity.jq
"The three dogs are named Benjamin, Samba, and Bernie."

Variable names:

"Benjamin" as $dog | "Samba" as $Dog | "Bernie" as $DOG
 | "The three dogs are named \($dog), \($Dog), and \($DOG)."

Output:

As above.

Julia

Works with: Julia version 0.6

Variable names are case sensitive.

dog, Dog, DOG = "Benjamin", "Samba", "Bernie"

if dog === Dog
    println("There is only one dog, ", DOG)
else
    println("The three dogs are:  ", dog, ", ", Dog, " and ", DOG)
end

Output:

The three dogs are:  Benjamin, Samba and Bernie

Conventionally, variable names should be all lower case. Type and Macro names should be capitalized.

K

  dog: "Benjamin"
  Dog: "Samba"
  DOG: "Bernie"
  "There are three dogs named ",dog,", ",Dog," and ",DOG
"There are three dogs named Benjamin, Samba and Bernie"

Kotlin

Kotlin is case-sensitive though (as in Java) the convention is for local variable names to begin with a lower case letter. The second and third identifiers would therefore be unlikely to be used in practice.

fun main(args: Array<String>) {
    val dog = "Benjamin"
    val Dog = "Samba"
    val DOG = "Bernie"
    println("The three dogs are named $dog, $Dog and $DOG")
}

Output:

The three dogs are named Benjamin, Samba and Bernie

Lasso

Lasso is not case sensitive for names

local(dog = 'Benjamin')
local(Dog = 'Samba')
local(DOG = 'Bernie')

stdoutnl('There is just one dog named ' + #dog)

Output:

There is just one dog named Bernie

Same with string comparisons. (Lasso maps can only contain unique keys)

local(dogs = map(
	'dog' = 'Benjamin',
	'Dog' = 'Samba',
	'DOG' = 'Bernie'
))
stdoutnl(#dogs -> size)

Output:

1

To get case sensitivity we need to use bytes

local(dogs = map(
	bytes('dog') = 'Benjamin',
	bytes('Dog') = 'Samba',
	bytes('DOG') = 'Bernie'
))

stdoutnl(#dogs -> size)

stdoutnl(#dogs -> find(bytes('Dog')))

Output:

3
Samba 

Logtalk

In Logtalk, as in the underlying Prolog, variables must begin with an uppercase character or an underscore. Thus the task as written cannot be performed but an analogous one can be.

:- object(three_dogs_or_one).

    :- public(test/0).

    test :- 
        fill_dogs(DOG, Dog, DoG),
        write_message(DOG, Dog, DoG).

    % Note: this predicate would actually fail if variables weren't case sensitive...
    fill_dogs('Benjamin', 'Samba', 'Bernie').

    % Note: ...as a result there is no way for this clause to ever succeed.
    write_message(A, A, A) :-
       format('There is one dog named ~w.~n', [A]).

    write_message(A, B, C) :-
       A \= B, B \= C, A \= C,
       format('There are three dogs named ~w, ~w, and ~w.~n', [A, B, C]).

:- end_object.

Output:

?- {dogs}.
% ... messages elided
?- true.

?- three_dogs_or_one::test.
There are three dogs named Benjamin, Samba, and Bernie.
true.
?-

Lua

dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"

print( "There are three dogs named "..dog..", "..Dog.." and "..DOG.."." )

There are three dogs named Benjamin, Samba and Bernie.

M2000 Interpreter

Labels are case sensitive, but identifiers are not case sensitive. Keys in Inventory are case sensitive Types in Enumeration are case sensitive, identifiers are not case sensitive.

MoDuLe CheckIT {
      \\ keys as case sensitive if they are strings
      Inventory A= "Dog":=1, "dog":=2,"DOG":="Hello", 100:="Dog"
      Print A("Dog"), A("dog"), A$("DOG"), A$(100)
      
      \\ Enumeration get type as defined (same case)
      Enum Dogs {Benjamin, Samba, Bernie}
      Print Type$(Bernie)="Dogs"
      Print Type$(DOGS)="Dogs"
      m=BenJamiN
      m++
      Print Eval$(m)="Samba"  ' same case as defined
      
      DoG$="Benjamin"
      DOG$="Samba"
      doG$="Bernie"
      PrinT "There is just one dog named "+Dog$+"."
      goto Dog
dog:
      Print "dog"
      Exit
Dog:   
      Print "Dog"   
      GoTo dog
}
Checkit

Maple

> dog, Dog, DOG := "Benjamin", "Samba", "Bernie":
> if nops( { dog, Dog, DOG } ) = 3 then
>   printf( "There are three dogs named %s, %s and %s.\n", dog, Dog, DOG )
> elif nops( { dog, Dog, DOG } ) = 2 then
>   printf( "WTF? There are two dogs named %s and %s.\n", op( { dog, Dog, DOG } ) )
> else
>   printf( "There is one dog named %s.\n", dog )
> end if:
There are three dogs named Benjamin, Samba and Bernie.

Mathematica / Wolfram Language

dog = "Benjamin"; Dog = "Samba"; DOG = "Bernie";
"The three dogs are named "<> dog <>", "<> Dog <>" and "<> DOG 

-> "The three dogs are named Benjamin, Samba and Bernie"

MATLAB / Octave

  dog = 'Benjamin';
  Dog = 'Samba';
  DOG = 'Bernie';

  printf('There are three dogs %s, %s, %s.\n',dog, Dog, DOG);

Output

  There are three dogs Benjamin, Samba, Bernie.  

Maxima

/* Maxima is case sensitive */
a: 1$
A: 2$

is(a = A);
false

min

Works with: min version 0.37.0

min's symbols are case sensitive.

"Benjamin" :dog
"Samba" :Dog
"Bernie" :DOG

"There are three dogs named $1, $2, and $3." (dog Dog DOG) =% puts!

Output:

There are three dogs named Benjamin, Samba, and Bernie.

MiniScript

dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"

print "There are three dogs named " + dog + ", " + Dog + " and " + DOG

Modula-2

MODULE  dog;

IMPORT  InOut;

TYPE    String          = ARRAY [0..31] OF CHAR;

VAR     dog, Dog, DOG   : String;

(* No compiler error, so the rest is simple  *)

BEGIN
  InOut.WriteString ("Three happy dogs.");
  InOut.WriteLn
END dog.

N/t/roff

In groff, string variables are case sensitive.

.ds dog Benjamin
.ds Dog Samba
.ds DOG Bernie
The three dogs are named \*[dog], \*[Dog] and \*[DOG].

Output:

The three dogs are named Benjamin, Samba and Bernie.

Nanoquery

dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"

print format("The three dogs are named %s, %s, and %s.\n", dog, Dog, DOG)

Output:

The three dogs are named Benjamin, Samba, and Bernie.

Nemerle

def dog = "Benjamin";
def Dog = "Samba";
def DOG = "Bernie";
WriteLine($"The three dogs are named $dog, $Dog, and $DOG");

NESL

NESL is completely case-insensitive.

dog = "Benjamin";
Dog = "Samba";
DOG = "Bernie";
"There is just one dog, named " ++ dog;

Output:

it = "There is just one dog, named Bernie" : [char]

NetRexx

NetRexx is not case sensitive:

/* NetRexx */
options replace format comments java crossref symbols nobinary

dog = "Benjamin";
Dog = "Samba";
DOG = "Bernie";

if dog == Dog & Dog == DOG & dog == DOG then do
  say 'There is just one dog named' dog'.'
  end
else do
  say 'The three dogs are named' dog',' Dog 'and' DOG'.'
  end

return

Output:

There is just one dog named Bernie.

Nim

Nim has peculiar rules regarding case and style sensitivity:

– it is mainly a case insensitive language;

– but keywords are all in lowercase;

– and the first letter of an identifier is case sensitive;

– moreover, underline is ignored in identifiers (style insensitivity).

With these rules, we don’t get one dog or three dogs: we get two dogs!

var dog, Dog: string
(dog, Dog, DOG) = ("Benjamin", "Samba", "Bernie")
 
if dog == Dog:
  if dog == DOG:
    echo "There is only one dog, ", DOG)
  else:
    echo "There are two dogs: ", dog, " and ", DOG
elif Dog == DOG :
  echo "There are two dogs: ", dog, " and ", DOG
else:
  echo "There are three dogs:  ", dog, ", ", Dog, " and ", DOG

Output:

There are two dogs: Benjamin and Bernie

Oberon-2

Works with: oo2c Version 2

MODULE CaseSensitivity;
IMPORT
  Out;
VAR
  dog, Dog, DOG: STRING;
BEGIN  
  dog := "Benjamin";
  Dog := "Samba";
  DOG := "Bernie";
  Out.Object("The three dogs are named " + dog + ", " + Dog + " and " + DOG);
  Out.Ln
END CaseSensitivity.

Output:

The three dogs are named Benjamin, Samba and Bernie

Objeck

Objeck is case sensitive

class Program {
  function : Main(args : String[]) ~ Nil {
    dog := "Benjamin";
    Dog := "Samba";
    DOG := "Bernie";
    "The three dogs are named {$dog}, {$Dog}, and {$DOG}."->PrintLine();
  }
}

OCaml

Identifiers in OCaml are lettercase sensitive, but the first letter has to be lowercase.

let () =
  let dog = "Benjamin" in
  let dOG = "Samba" in
  let dOg = "Bernie" in
  Printf.printf "The three dogs are named %s, %s and %s.\n" dog dOG dOg

Oforth

Oforth is case-sensitive.

: threeDogs
| dog Dog DOG |

   "Benjamin" ->dog
   "Samba"  ->Dog
   "Bernie" ->DOG

   System.Out "The three dogs are named " << dog << ", " << Dog << " and " << DOG << "." << cr ;

Ol

(define dog "Benjamin")
(define Dog "Samba")
(define DOG "Bernie")
	
(print "The three dogs are named " dog ", " Dog " and " DOG ".\n")

Output:

The three dogs are named Benjamin, Samba and Bernie.

PARI/GP

dog="Benjamin";
Dog="Samba";
DOG="Bernie";
printf("The three dogs are named %s, %s, and %s.", dog, Dog, DOG)

Pascal

See Delphi

PascalABC.NET

See Delphi

Perl

# These variables are all different
$dog='Benjamin';
$Dog='Samba';
$DOG='Bernie';
print "The three dogs are named $dog, $Dog, and $DOG \n"

Phix

Library: Phix/basics

Phix is case sensitive

sequence dog = "Benjamin",
         Dog = "Samba",
         DOG = "Bernie"
printf( 1, "The three dogs are named %s, %s and %s\n", {dog, Dog, DOG} )

Output:

The three dogs are named Benjamin, Samba and Bernie

PHP

<?php

// In true PHP style, this example is inconsistent.
// Variable identifiers are case sensitive

$dog = 'Benjamin';
$Dog = 'Samba';
$DOG = 'Bernie';

echo "There are 3 dogs named {$dog}, {$Dog} and {$DOG}\n";

// Whereas function identifiers are case insensitive

function DOG() { return 'Bernie'; }

echo 'There is only 1 dog named ' . dog() . "\n";

Output:

There are 3 dogs named Benjamin, Samba and Bernie
There is only 1 dog named Bernie

PicoLisp

(let (dog "Benjamin"  Dog "Samba"  DOG "Bernie")
   (prinl "The three dogs are named " dog ", " Dog " and " DOG) )

Output:

The three dogs are named Benjamin, Samba and Bernie

PL/I

*process or(!) source xref attributes macro options;
 /*********************************************************************
 * Program to show that PL/I is case-insensitive
 * 28.05.2013 Walter Pachl
 *********************************************************************/
 case: proc options(main);
 Dcl dog Char(20) Var;
 dog = "Benjamin";
 Dog = "Samba";
 DOG = "Bernie";
 Put Edit(dog,Dog,DOG)(Skip,3(a,x(1)));
 End;

Output

Bernie Bernie Berni

Plain English

Plain English is NOT case sensitive.

To run:
Start up.
Put "Benjamin" into a DOG string.
Put "Samba" into the Dog string.
Put "Bernie" into the dog string.
Write "There is just one dog named " then the DOG on the console.
Wait for the escape key.
Shut down.

Output:

There is just one dog named Bernie

PowerShell

PowerShell is not case sensitive.

$dog = "Benjamin"
$Dog = "Samba"
$DOG = "Bernie"

"There is just one dog named {0}." -f $dOg

Output:

There is just one dog named Bernie.

Prolog

In Prolog, the initial of a variable must be a uppercase letter. So the task can't be completed but we can write this code :

three_dogs :-
	DoG = 'Benjamin',
	Dog = 'Samba',
	DOG = 'Bernie',
	format('The three dogs are named ~w, ~w and ~w.~n', [DoG, Dog, DOG]).

The output is :

?- three_dogs.
The three dogs are named Benjamin, Samba and Bernie.
true.

Python

Python variable names are case sensitive:

dog = 'Benjamin'
Dog = 'Samba'
DOG = 'Bernie'

print(f"The three dogs are named {dog}, {Dog} and {DOG}.")

Quackery

[ $ 'Benjamin' ] is dog ( --> $ )

[ $ 'Samba' ]    is Dog ( --> $ )

[ $ 'Bernie' ]   is DOG ( --> $ )

say 'There are three dogs named '
dog echo$ say ', '
Dog echo$ say ', and '
DOG echo$ say '.' cr

Output:

There are three dogs named Benjamin, Samba, and Bernie.

R

dog <- 'Benjamin'
Dog <- 'Samba'
DOG <- 'Bernie'

# Having fun with cats and dogs 
cat('The three dogs are named ')
cat(dog)
cat(', ')
cat(Dog)
cat(' and ')
cat(DOG)
cat('.\n')
# In one line it would be:
# cat('The three dogs are named ', dog, ', ', Dog, ' and ', DOG, '.\n', sep = '')

Output:

The three dogs are named Benjamin, Samba and Bernie.

Racket

The default setting for the Racket reader is to be case sensitive:

#lang racket
(define dog "Benjamin")
(define Dog "Samba")
(define DOG "Bernie")
 
(if (equal? dog DOG)
    (displayln (~a "There is one dog named " DOG "."))
    (displayln (~a "The three dogs are named " dog ", " Dog ", and, " DOG ".")))

Output:

The three dogs are named Benjamin, Samba, and, Bernie.

If you need case insensitive identifiers, then use #ci to turn on case insensitivity:

#lang racket
#ci(module dogs racket
     (define dog "Benjamin")
     (set! Dog "Samba")
     (set! DOG "Bernie")     
     (if (equal? dog DOG)
         (displayln (~a "There is one dog named " DOG "."))
         (displayln (~a "The three dogs are named " dog ", " Dog ", and, " DOG "."))))
(require 'dogs)

Output:

There is one dog named Bernie.

Raku

(formerly Perl 6)

my $dog = 'Benjamin';
my $Dog = 'Samba';
my $DOG = 'Bernie';
say "The three dogs are named $dog, $Dog, and $DOG."

The only place that Raku pays any attention to the case of identifiers is that, for certain error messages, it will guess that an identifier starting lowercase is probably a function name, while one starting uppercase is probably a type or constant name. But this case distinction is merely a convention in Raku, not mandatory:

constant dog = 'Benjamin';
sub Dog() { 'Samba' }
my &DOG = { 'Bernie' }
say "The three dogs are named {dog}, {Dog}, and {DOG}."

Retro

Retro is case sensitive.

: dog  ( -$ )  "Benjamin" ;
: Dog  ( -$ )  "Samba" ;
: DOG  ( -$ )  "Bernie" ;

DOG Dog dog "The three dogs are named %s, %s, and %s.\n" puts

REXX

simple variables

The REXX language is case insensitive   (with respect to simple variables).

/*REXX program demonstrate  case insensitivity  for  simple  REXX  variable names.      */

  /*  ┌──◄── all 3 left─hand side REXX variables are identical (as far as assignments). */
  /*  │                                                                                 */
  /*  ↓                                                                                 */
     dog= 'Benjamin'                             /*assign a   lowercase   variable (dog)*/
     Dog= 'Samba'                                /*   "   "  capitalized     "      Dog */
     DOG= 'Bernie'                               /*   "   an  uppercase      "      DOG */

                              say center('using simple variables', 35, "─")     /*title.*/
                              say

if dog\==Dog | DOG\==dog  then say 'The three dogs are named:'     dog"," Dog 'and' DOG"."
                          else say 'There is just one dog named:'  dog"."

                                                 /*stick a fork in it,  we're all done. */

output

──────using simple variables───────

There is just one dog named: Bernie.

compound variables

However, the REXX language is case sensitive   (with respect to compound variables, or indices).

/*REXX program demonstrate case sensitive REXX  index  names  (for compound variables). */

 /*  ┌──◄── all 3 indices (for an array variable)  are unique  (as far as array index). */
 /*  │                                                                                  */
 /*  ↓                                                                                  */
x= 'dog';  dogname.x= "Gunner"                   /*assign an array index,  lowercase dog*/
x= 'Dog';  dogname.x= "Thor"                     /*   "    "   "     "   capitalized Dog*/
x= 'DOG';  dogname.x= "Jax"                      /*   "    "   "     "     uppercase DOG*/
x= 'doG';  dogname.x= "Rex"                      /*   "    "   "     "       mixed   doG*/

                              say center('using compound variables', 35, "═")   /*title.*/
                              say

_= 'dog';  say "dogname.dog="  dogname._         /*display an array index, lowercase dog*/
_= 'Dog';  say "dogname.Dog="  dogname._         /*   "     "   "     "  capitalized Dog*/
_= 'DOG';  say "dogname.DOG="  dogname._         /*   "     "   "     "    uppercase DOG*/
_= 'doG';  say "dogname.doG="  dogname._         /*   "     "   "     "      mixed   doG*/

                                                 /*stick a fork in it,  we're all done. */

output

═════using compound variables══════

dogname.dog= Gunner
dogname.Dog= Thor
dogname.DOG= Jax
dogname.doG= Rex

Ring

dog = "Benjamin"
doG = "Smokey"
Dog = "Samba"
DOG = "Bernie"
see "The 4 dogs are : " + dog +  ", " + doG + ", " + Dog + " and " + DOG + "."

RPL

RPL designers recommend to use lowercase for local variables, whilst uppercase shall be used for global variables and programs.

≪ "Samba" 'DOG' STO → "Benjamin" "Bernie" Dog dog
  ≪ IF DOG dog == THEN 
       "Just 1 dog named " DOG +
     ELSE
       "3 dogs: " Dog + ", " + DOG + " & " + dog +
     END
≫ ≫ EVAL

Output:

1: "3 dogs: Benjamin, Samba & Bernie"

Ruby

Ruby gives a special meaning to the first letter of a name. A lowercase letter starts a local variable. An uppercase letter starts a constant. So dog is a local variable, but Dog and DOG are constants. To adapt this task to Ruby, I added dOg and doG so that I have more than one local variable.

module FiveDogs
  dog = "Benjamin"
  dOg = "Dogley"
  doG = "Fido"
  Dog = "Samba"   # this constant is FiveDogs::Dog
  DOG = "Bernie"  # this constant is FiveDogs::DOG

  names = [dog, dOg, doG, Dog, DOG]
  names.uniq!
  puts "There are %d dogs named %s." % [names.length, names.join(", ")]
  puts
  puts "The local variables are %s." % local_variables.join(", ")
  puts "The constants are %s." % constants.join(", ")
end

Output:

There are 5 dogs named Benjamin, Dogley, Fido, Samba, Bernie.

The local variables are dog, dOg, doG, names.
The constants are Dog, DOG.

Rust

Rust style dictates that identifiers should be written in snake case, e.g. big_dog, small_dog; whereas types (structs and enums) should be written in camel case, e.g. BigDog, SmallDog. Failing to comply with this standard does not cause a compiler error, but it will trigger a compiler warning, and the culture is very strongly towards compliance with this standard.

fn main() {
    let dog = "Benjamin";
    let Dog = "Samba";
    let DOG = "Bernie";
    println!("The three dogs are named {}, {} and {}.", dog, Dog, DOG);
}

This triggers two warnings at compilation:

<anon>:3:9: 3:12 warning: variable `Dog` should have a snake case name such as `dog`, #[warn(non_snake_case)] on by default
<anon>:3     let Dog = "Samba";
                 ^~~
<anon>:4:9: 4:12 warning: variable `DOG` should have a snake case name such as `dog`, #[warn(non_snake_case)] on by default
<anon>:4     let DOG = "Bernie";
                 ^~~

The resulting program will compile and run just fine, producing the output:

The three dogs are named Benjamin, Samba and Bernie.

Sather

Though by convention Sather uses all uppercase letters for class names, a variable can be all uppercase.

class MAIN is
  main is
    dog ::= "Benjamin";
    Dog ::= "Samba";
    DOG ::= "Bernie";
    #OUT + #FMT("The three dogs are %s, %s and %s\n", 
                 dog, Dog, DOG);
  end;
end;

Outputs:

The three dogs are Benjamin, Samba and Bernie

Scala

val dog = "Benjamin"
val Dog = "Samba"
val DOG = "Bernie"
println("There are three dogs named " + dog + ", " + Dog + ", and " + DOG + ".")

Output:

There are three dogs named Benjamin, Samba, and Bernie.

Scheme

Output may differ depending on implementation.

(define dog "Benjamin")
(define Dog "Samba")
(define DOG "Bernie")

(if (eq? dog DOG)
        (begin (display "There is one dog named ")
                (display DOG)
                (display ".")
                (newline))
        (begin (display "The three dogs are named ")
                (display dog) (display ", ")
                (display Dog) (display " and ")
                (display DOG)
                (display ".")
                (newline)))

Seed7

$ include "seed7_05.s7i";

const string: dog is "Benjamin";
const string: Dog is "Samba";
const string: DOG is "Bernie";

const proc: main is func
  begin
    writeln("The three dogs are named " <& dog <& ", " <& Dog <& " and " <& DOG <& ".");
  end func;

SenseTalk

As a People Oriented Programming language, SenseTalk's variable names are case-insensitive.

set dog to "Benjamin"
set Dog to "Samba"
set DOG to "Bernie"

put !"There is just one dog named [[dog]]."

Output:

There is just one dog named Bernie.

SETL

dog := 'Benjamin';
Dog := 'Samba';
DOG := 'Bernie';
print( 'There is just one dog named', dOg );

Output:

There is just one dog named Bernie

Sidef

var dog = 'Benjamin';
var Dog = 'Samba';
var DOG = 'Bernie';
say "The three dogs are named #{dog}, #{Dog}, and #{DOG}.";

Output:

The three dogs are named Benjamin, Samba, and Bernie.

Simula

Simula identifiers are case-insensitive, and the compiler will indignantly reject a program that tries to declare multiple variables with names differing only in case. (Same with key words: Case of a character in Simula code generally only matters in a simple string or a character constant.)

begin
    text dog;
    dog :- blanks( 8 );
    dog := "Benjamin";
    Dog := "Samba";
    DOG := "Bernie";
    outtext( "There is just one dog, named " );
    outtext( dog );
    outimage
end

Output:

There is just one dog, named Bernie

Smalltalk

Works with: GNU Smalltalk

Smalltalk's symbols are case sensitive.

|dog Dog DOG|
dog := 'Benjamin'.
Dog := 'Samba'.
DOG := 'Bernie'.
( 'The three dogs are named %1, %2 and %3' %
  { dog . Dog . DOG } ) displayNl.

Outputs:

The three dogs are named Benjamin, Samba and Bernie

SNOBOL4

    DOG = 'Benjamin'
    Dog = 'Samba'
    dog = 'Bernie'
    OUTPUT = 'The three dogs are named ' DOG ', ' Dog ', and ' dog
END

Output:

The three dogs are named Benjamin, Samba, and Bernie

Standard ML

Standard ML is case sensitive.

let
  val dog = "Benjamin"
  val Dog = "Samba"
  val DOG = "Bernie"
in
  print("The three dogs are named " ^ dog ^ ", " ^ Dog ^ ", and " ^ DOG ^ ".\n")
end;

Output:

The three dogs are named Benjamin, Samba, and Bernie.

Stata

Stata is case-sensitive.

. local dog Benjamin
. local Dog Samba
. local DOG Bernie
. display "The three dogs are named $_dog, $_Dog, and $_DOG."
The three dogs are named Benjamin, Samba, and Bernie.

Swift

let dog = "Benjamin"
let Dog = "Samba"
let DOG = "Bernie"
println("The three dogs are named \(dog), \(Dog), and \(DOG).")

Tcl

Tcl variable names are case sensitive:

set dog "Benjamin"
set Dog "Samba"
set DOG "Bernie"
puts "The three dogs are named $dog, $Dog and $DOG"

Which prints...

The three dogs are named Benjamin, Samba and Bernie

UNIX Shell

dog="Benjamin"
Dog="Samba"
DOG="Bernie"
echo "The three dogs are named $dog, $Dog and $DOG."

The three dogs are named Benjamin, Samba and Bernie.

Ursa

Ursa names are case sensitive:

> decl string dog Dog DOG
> set dog "Benjamin"
> set Dog "Samba"
> set DOG "Bernie"
> out "The three dogs are named " dog ", "  Dog ", and " DOG endl console
The three dogs are named Benjamin, Samba, and Bernie
>

VBA

VBA is case sensitive case insensitive. The variable names 'dog', 'Dog' and 'DOG' can not co-exist.

Public Sub case_sensitivity()
    'VBA does not allow variables that only differ in case
    'The VBA IDE vbe will rename variable 'dog' to 'DOG'
    'when trying to define a second variable 'DOG'
    Dim DOG As String
    DOG = "Benjamin"
    DOG = "Samba"
    DOG = "Bernie"
    Debug.Print "There is just one dog named " & DOG
End Sub

Output:

There is just one dog named Bernie

Wren

Identifiers in Wren are case sensitive.

var dog = "Benjamin"
var Dog = "Samba"
var DOG = "Bernie"
System.print("The three dogs are named %(dog), %(Dog) and %(DOG).")

Output:

The three dogs are named Benjamin, Samba and Bernie.

XBS

In XBS variable names are case-sensitive.

set dog="Benjamin";
set DOG="Samba";
set Dog="Bernie";
log(`The three dogs are named {dog}, {DOG} and {Dog}.`);

Output:

The three dogs are named Benjamin, Samba and Bernie.

XLISP

XLISP is entirely case-insensitive. The user can decide whether to have the system print symbols, etc., in capitals or in lower case, by assigning to the variable *PRINT-CASE*.

(SETQ DOG 'BENJAMIN)
(SETQ Dog 'SAMBA)
(SETQ dog 'BERNIE)
(DISPLAY `(THERE IS JUST ONE DOG NAMED ,DOG))

There is, in any event, only one dog.

(THERE IS JUST ONE DOG NAMED BERNIE)

XPL0

XPL0 is normally case-insensitive, so there is really just one dog named Bernie. However, it has a command-line switch (/c) that turns case sensitivity on. All names must start with a capital letter (or an underline, so they can't clash with command words such as 'for'). Thus "dog" cannot be used as a name, but Dog, DOG and DoG (and For) can. The intent of the command-line switch (/c) is to detect inconsistent capitalizing of names such as Ascii and ASCII or CpuReg and CPUReg.

Zig

In Zig identifiers are case-sensitive.

const std = @import("std");

pub fn main() void {
    const dog = "Benjamin";
    const Dog = "Samba";
    const DOG = "Bernie";

    std.debug.print("The three dogs are named {s}, {s}, and {s}.\n", .{ dog, Dog, DOG });
}

Output:

The three dogs are named Benjamin, Samba, and Bernie.

zkl

var dog = "Benjamin", Dog = "Samba", DOG = "Bernie";

Output:

vars
L(L("DOG","Bernie"),L("Dog","Samba"),L("dog","Benjamin"))