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Non-decimal radices/Input

From Rosetta Code
Task
Non-decimal radices/Input
You are encouraged to solve this task according to the task description, using any language you may know.

It is common to have a string containing a number written in some format, with the most common ones being decimal, hexadecimal, octal and binary. Such strings are found in many places (user interfaces, configuration files, XML data, network protocols, etc.)

This task requires parsing of such a string (which may be assumed to contain nothing else) using the language's built-in facilities if possible. Parsing of decimal strings is required, parsing of other formats is optional but should be shown (i.e., if the language can parse in base-19 then that should be illustrated).

The solutions may assume that the base of the number in the string is known. In particular, if your language has a facility to guess the base of a number by looking at a prefix (e.g. "0x" for hexadecimal) or other distinguishing syntax as it parses it, please show that.

The reverse operation is in task Non-decimal radices/Output

For general number base conversion, see Non-decimal radices/Convert.

Ada[edit]

Ada supports the input format <BASE>#<VALUE>#, for example 16#AF42# or 2#1010110# or 8#777#. This can be used for input through Ada.Text_IO.Integer_IO or for conversion through Integer'Value. More details on this format can be found here: Ada 2005 Reference Manual - 2.4.2 Based Literals.

Limited to Bases 2 to 16.

Works with Float values, too.

numbers.adb:

with Ada.Text_IO;
procedure Numbers is
package Int_IO is new Ada.Text_IO.Integer_IO (Integer);
package Float_IO is new Ada.Text_IO.Float_IO (Float);
begin
Int_IO.Put (Integer'Value ("16#ABCF123#"));
Ada.Text_IO.New_Line;
Int_IO.Put (Integer'Value ("8#7651#"));
Ada.Text_IO.New_Line;
Int_IO.Put (Integer'Value ("2#1010011010#"));
Ada.Text_IO.New_Line;
Float_IO.Put (Float'Value ("16#F.FF#E+2"));
Ada.Text_IO.New_Line;
end Numbers;

Output:

  180154659
       4009
        666
 4.09500E+03

Aime[edit]

o_integer(alpha("f4240", 16));
o_byte('\n');
o_integer(alpha("224000000", 5));
o_byte('\n');
o_integer(alpha("11110100001001000000", 2));
o_byte('\n');
 
o_integer(alpha("03641100", 0));
o_byte('\n');
o_integer(alpha("0xf4240", 0));
o_byte('\n');

ALGOL 68[edit]

Translation of: C
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny
main:
(
FILE fbuf; STRING sbuf;
 
OP FBUF = (STRING in sbuf)REF FILE: (
sbuf := in sbuf;
associate(fbuf, sbuf);
fbuf
);
 
BITS num;
 
getf(FBUF("0123459"), ($10r7d$, num));
printf(($gl$, ABS num)); # prints 123459 #
 
getf(FBUF("abcf123"), ($16r7d$, num));
printf(($gl$, ABS num)); # prints 180154659 #
 
getf(FBUF("7651"), ($8r4d$, num));
printf(($gl$, ABS num)); # prints 4009 #
 
getf(FBUF("1010011010"), ($2r10d$, num));
printf(($gl$, ABS num)) # prints 666 #
 
)

Output:

    +123459
 +180154659
      +4009
       +666

AutoHotkey[edit]

There is no built in support for generic base parsing.
Please see Number base conversion

BBC BASIC[edit]

      REM VAL parses decimal strings:
PRINT VAL("0")
PRINT VAL("123456789")
PRINT VAL("-987654321")
 
REM EVAL can be used to parse binary and hexadecimal strings:
PRINT EVAL("%10101010")
PRINT EVAL("%1111111111")
PRINT EVAL("&ABCD")
PRINT EVAL("&FFFFFFFF")

Output:

         0
 123456789
-987654321
       170
      1023
     43981
        -1

C[edit]

In addition to strtol() described in the Number base conversion task, you could also use the scanf family of functions to parse un-prefixed hexadecimal, decimal, and octal numbers:

#include <stdio.h>
 
int main()
{
int num;
 
sscanf("0123459", "%d", &num);
printf("%d\n", num); /* prints 123459 */
 
sscanf("abcf123", "%x", &num);
printf("%d\n", num); /* prints 180154659 */
 
sscanf("7651", "%o", &num);
printf("%d\n", num); /* prints 4009 */
 
/* binary not supported */
 
return 0;
}

The strtol() function can also parse prefixed hexadecimal, octal, and decimal strings based on the prefix, when passed a base of 0:

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
 
int main()
{
int num;
char *endptr;
 
num = strtol("123459", &endptr, 0);
assert(*endptr == '\0');
printf("%d\n", num); /* prints 123459 */
 
num = strtol("0xabcf123", &endptr, 0);
assert(*endptr == '\0');
printf("%d\n", num); /* prints 180154659 */
 
num = strtol("07651", &endptr, 0);
assert(*endptr == '\0');
printf("%d\n", num); /* prints 4009 */
 
/* binary not supported */
 
return 0;
}

C#[edit]

using System;
 
class Program
{
static void Main()
{
var value = "100";
var fromBases = new[] { 2, 8, 10, 16 };
var toBase = 10;
foreach (var fromBase in fromBases)
{
Console.WriteLine("{0} in base {1} is {2} in base {3}",
value, fromBase, Convert.ToInt32(value, fromBase), toBase);
}
}
}

Output:

100 in base 2 is 4 in base 10
100 in base 8 is 64 in base 10
100 in base 10 is 100 in base 10
100 in base 16 is 256 in base 10

C++[edit]

#include <iostream>
#include <sstream>
 
int main()
{
int num;
 
std::istringstream("0123459") >> num;
std::cout << num << std::endl; // prints 123459
 
std::istringstream("0123459") >> std::dec >> num;
std::cout << num << std::endl; // prints 123459
 
std::istringstream("abcf123") >> std::hex >> num;
std::cout << num << std::endl; // prints 180154659
 
std::istringstream("7651") >> std::oct >> num;
std::cout << num << std::endl; // prints 4009
 
// binary not supported
 
return 0;
}

Common Lisp[edit]

(parse-integer "abc" :radix 20 :junk-allowed t) ; => 4232

If :radix is omitted, it defaults to 10. If :junk-allowed is omitted, it defaults to nil, causing #'parse-integer to signal an error of type parse-error rather than just returning nil whenever the input string isn't a numeral possibly surrounded by whitespace.

D[edit]

Translation of: Python
import std.stdio, std.conv;
 
void main() {
immutable text = "100";
foreach (base; 2 .. 21)
writefln("String '%s' in base %d is  %d in base 10" ,
text, base, to!int(text, base));
}
Output:
String '100' in base 2 is  4 in base 10
String '100' in base 3 is  9 in base 10
String '100' in base 4 is  16 in base 10
String '100' in base 5 is  25 in base 10
String '100' in base 6 is  36 in base 10
String '100' in base 7 is  49 in base 10
String '100' in base 8 is  64 in base 10
String '100' in base 9 is  81 in base 10
String '100' in base 10 is  100 in base 10
String '100' in base 11 is  121 in base 10
String '100' in base 12 is  144 in base 10
String '100' in base 13 is  169 in base 10
String '100' in base 14 is  196 in base 10
String '100' in base 15 is  225 in base 10
String '100' in base 16 is  256 in base 10
String '100' in base 17 is  289 in base 10
String '100' in base 18 is  324 in base 10
String '100' in base 19 is  361 in base 10
String '100' in base 20 is  400 in base 10

E[edit]

? __makeInt("200", 16)
# value: 512
 
? __makeInt("200", 10)
# value: 200

Elixir[edit]

base: 2 .. 36

iex(1)> String.to_integer("1000")
1000
iex(2)> String.to_integer("1000",2)
8
iex(3)> String.to_integer("1000",8)
512
iex(4)> String.to_integer("1000",16)
4096
iex(5)> String.to_integer("ffff",16)
65535

Erlang[edit]

My interpretation of the task description is that I can state that the base (here: 17) can be 2..36, without having to show one example of each.

Output:
<12> erlang:list_to_integer("ffff", 17).
78300

F#[edit]

let value = "100"
let fromBases = [ 2; 8; 10; 16 ]
let values = Seq.initInfinite (fun i -> value)
Seq.zip fromBases (Seq.zip values fromBases |> Seq.map (System.Convert.ToInt32))
|> Seq.iter (
fun (fromBase, valueFromBaseX) ->
printfn "%s in base %i is %i in base 10" value fromBase valueFromBaseX)
Output:
100 in base 2 is 4 in base 10
100 in base 8 is 64 in base 10
100 in base 10 is 100 in base 10
100 in base 16 is 256 in base 10

Factor[edit]

Bases from 2 to 16 are supported through the generic base> word (see online docs [1]) but 4 functions are defined for the most used cases:

   ( scratchpad ) "ff" hex> . ! base 16
   255
   ( scratchpad ) "777" oct> . ! base 8
   511
   ( scratchpad ) "1111" bin> . ! base 2
   15
   ( scratchpad ) "99" string>number . ! base 10
   99

Note that these words are very simple : for example, here's oct> :

IN: math.parser
: oct> ( str -- n/f ) 8 base> ; inline

Also, fractions are handled transparently :

   ( scratchpad ) "1+F/2" hex> .
   8+1/2

Hex floats are supported, anything else is taken as base 10 :

   ( scratchpad ) "ff.f" hex> .
   255.9375
   ( scratchpad ) "11.1101" bin> .
   11.1101

Forth[edit]

Arbitrary base 2-36 parsing is supported by the same mechanism as decimal parsing: set the user variable BASE to the desired base, then scan the number. There are two convenience words for setting the base to DECIMAL or HEX.

: parse# ( str len -- u true | false )
0. 2SWAP DUP >R >NUMBER NIP NIP
R> <> DUP 0= IF NIP THEN ;
 
: base# ( str len base -- u true | false )
BASE @ >R BASE ! parse# R> BASE ! ;

Fortran[edit]

Works with: Fortran version 90 and later
program Example
implicit none
 
integer :: num
character(32) :: str
 
str = "0123459"
read(str, "(i10)") num ! Decimal
write(*,*) num ! Prints 123459
 
str = "abcf123"
read(str, "(z8)") num ! Hexadecimal
write(*,*) num ! Prints 180154659
 
str = "7651"
read(str, "(o11)") num ! Octal
write(*,*) num ! Prints 4009
 
str = "1010011010"
read(str, "(b32)") num ! Binary
write(*,*) num ! Prints 666
 
end program

FreeBASIC[edit]

FreeBASIC has built-in string to integer conversion functions which automatically recognize numbers in hexadecimal, decimal, octal or binary format provided that they are prefixed by &H, (nothing), &O and &B respectively. Here's an example:

' FB 1.05.0 Win64
 
Dim s(1 To 4) As String = {"&H1a", "26", "&O32", "&B11010"} '' 26 in various bases
For i As Integer = 1 To 4
Print s(i); Tab(9); "="; CInt(s(i))
Next
 
Sleep
Output:
&H1a    = 26
26      = 26
&O32    = 26
&B11010 = 26

Go[edit]

package main
 
import (
"fmt"
"math/big"
"strconv"
)
 
func main() {
// package strconv: the most common string to int conversion,
// base 10 only.
x, _ := strconv.Atoi("13")
fmt.Println(x)
 
// ParseInt handles arbitrary bases from 2 to 36, and returns
// a result of the requested size (64 bits shown here.)
// If the base argument is zero the base is determined by prefix
// as with math/big below.
x64, _ := strconv.ParseInt("3c2", 19, 64)
fmt.Println(x64)
 
// package fmt: allows direct conversion from strings, standard
// input, or from an io.Reader (file, buffer, etc) to integer types
// for bases 2, 8, 10, and 16 or to any type that implements the
// fmt.Scanner interface (e.g. a big.Int).
// (Fscanf and Scanf are more common for reading from
// an io.Reader or stdin than Sscanf for reading from strings.)
fmt.Sscanf("1101", "%b", &x)
fmt.Println(x)
 
fmt.Sscanf("15", "%o", &x)
fmt.Println(x)
 
fmt.Sscanf("13", "%d", &x)
fmt.Println(x)
 
fmt.Sscanf("d", "%x", &x)
fmt.Println(x)
 
// package math/big: allows conversion from string to big integer.
// any base from 2 to 36 can be specified as second parameter.
var z big.Int
z.SetString("111", 3)
fmt.Println(&z)
 
// if second parameter is 0, base is determined by prefix, if any
z.SetString("0b1101", 0) // 0b -> base 2
fmt.Println(&z)
 
z.SetString("015", 0) // 0 -> base 8
fmt.Println(&z)
 
z.SetString("13", 0) // no prefix -> base 10
fmt.Println(&z)
 
z.SetString("0xd", 0) // 0x -> base 16
fmt.Println(&z)
 
// As mentioned, a big.Int (or any type implementing fmt.Scanner)
// can also be use with any of the fmt scanning functions.
fmt.Sscanf("15", "%o", &z)
fmt.Println(&z)
}

Output is all 13s.

Haskell[edit]

Haskell's read can parse strings with the same prefix used for literals in Haskell (0x or 0X for hex, 0o or 0O for octal):

Prelude> read "123459" :: Integer
123459
Prelude> read "0xabcf123" :: Integer
180154659
Prelude> read "0o7651" :: Integer
4009

HicEst[edit]

READ(Text="123459    ", Format="i10") dec    ! 123459
READ(Text=" abcf123 ", Format="Z10") hex ! 180154659
READ(Text=" 7651 ", Format="o10") oct ! 4009
READ(Text=" 101011001", Format="B10.10") bin ! 345

Icon and Unicon[edit]

Icon allows numbers to be defined as 'root' + "R" + 'number', where 'root' is a base from 2 to 36, and 'number' is a string of digits or letters, using 'A' to 'Z' as appropriate for the base; case is ignored. Strings are automatically parsed into numbers when needed, using the procedure 'integer'.

 
procedure convert (str)
write (left(str, 10) || " = " || integer(str))
end
 
procedure main ()
convert (" 2r1001")
convert (" 8r7135")
convert ("16rABC1234")
convert ("36r1Z")
 
write ("2r1001" + "36r1Z") # shows type conversion, string->integer
end
 

Output:

 2r1001    = 9
 8r7135    = 3677
16rABC1234 = 180097588
36r1Z      = 71
80

J[edit]

Solution 1:
   baseN=: (, 'b'&,)&.":
Solution 2 (input sanitizing):
   baseN=: 0&".@,&": 'b' , ] NB.  Use if the source of the non-decimal "numbers" is not trustworthy
Example:
   16 baseN 'abcf123'
180154659
8 baseN '7651'
4009
10 baseN '123459'
123459

Note:

J also provides builtin support for numeric literals of an arbitrary base. The format is radixbdigits (where radix is specified in base 10). The one restriction is that you cannot use digits larger than 36 ('z'):
   16babcf123 8b7651 10b123459
180154659 4009 123459

However you can use digits larger than the radix:

   2bhelloworld
17955

And you can use bases where not all digits are representable:

   1000bogus
24016030028

Letters used for digits have base 10 values ranging from 10 (a) to 35 (z).

Java[edit]

Works with: Java version 1.5+

You must know the base that the String is in before you scan it. Create a Scanner in the usual way, but then set its radix to that base (obviously, the default is 10):

Scanner sc = new Scanner(System.in); //or any other InputStream or String
sc.useRadix(base); //any number from Character.MIN_RADIX (2) to CHARACTER.MAX_RADIX (36)
sc.nextInt(); //read in a value

Later you can call sc.reset() or sc.useRadix(10) to undo this change.

Another option using the Integer class:

int number = Integer.parseInt(stringNum, base);

The base here has the same restrictions as the Scanner example. A similar method is available in the Long class. Use no second argument for base 10.

If you have a prefixed string ("0x", "0X", or "#" for hex; "0" for octal; otherwise decimal), you can use the .decode() utility method to parse the number based on the base indicated by the prefix (note: this returns an Integer object, not a primitive int):

Integer.decode("0xabcf123"); // hex
Integer.decode("07651"); // octal
Integer.decode("123459"); // decimal

Long, Short, and Byte also have a .decode() method, to decode to the appropriate number object type.

JavaScript[edit]

For base 10 and 16 ("0x"-prefixed), (but not 8), it is fastest to parse strings using the unary plus (+) operator:

+"0123459"; // 123459
+"0xabcf123"; // 180154659
 
// also supports negative numbers, but not for hex:
+"-0123459"; // -123459
+"-0xabcf123"; // NaN

See http://www.jibbering.com/faq/notes/type-conversion/#tcNumber for more information.

The parseInt(string,radix) core function is the reverse of the number.toString(radix) method. The following is taken from Mozilla's JavaScript 1.5 reference.

The following examples all return 15:
parseInt(" 0xF", 16);
parseInt(" F", 16);
parseInt("17", 8);
parseInt(021, 8);
parseInt("015", 10);
parseInt(15.99, 10);
parseInt("FXX123", 16);
parseInt("1111", 2);
parseInt("15*3", 10);
parseInt("15e2", 10);
parseInt("15px", 10);
parseInt("12", 13);

The following examples all return NaN:

parseInt("Hello", 8); // Not a number at all
parseInt("546", 2); // Digits are not valid for binary representations

The following examples all return -15:

parseInt("-F", 16);
parseInt("-0F", 16);
parseInt("-0XF", 16);
parseInt(-10, 16);
parseInt(-15.1, 10)
parseInt(" -17", 8);
parseInt(" -15", 10);
parseInt("-1111", 2);
parseInt("-15e1", 10);
parseInt("-12", 13);

The following example returns 224:

parseInt("0e0", 16);

Although it is optional, most implementations interpret a numeric string beginning with a leading '0' as octal. The following may have an octal result.

parseInt("0e0"); // 0
parseInt("08"); // 0, '8' is not an octal digit.

Lua[edit]

Lua supports bases between 2 and 36.

print( tonumber("123") )
print( tonumber("a5b0", 16) )
print( tonumber("011101", 2) )
print( tonumber("za3r", 36) )

Mathematica[edit]

19^^91g5dcg2h6da7260a9f3c4a
->123456789012345678901234567890
 
2^^11110001001000000
->123456

MATLAB / Octave[edit]

val = sscanf('11 11 11','%d   %o  %x')

Output:

val =
   11
    9
   17

Nim[edit]

import strutils
 
echo parseInt "10" # 10
 
echo parseHexInt "0x10" # 16
echo parseHexInt "10" # 16
 
echo parseOctInt "0o120" # 80
echo parseOctInt "120" # 80

Output:

10
16
16
80
80

OCaml[edit]

The int_of_string function can parse hexadecimal, octal, and binary numbers that have the same prefix that is used to specify OCaml constants ("0x", "0o", and "0b", respectively):

# int_of_string "123459";;
- : int = 123459
# int_of_string "0xabcf123";;
- : int = 180154659
# int_of_string "0o7651";;
- : int = 4009
# int_of_string "0b101011001";;
- : int = 345

The Int32.of_string, Int64.of_string, and Nativeint.of_string functions also can understand the above prefixes when parsing into their appropriate types.

Starting in OCaml 4.02, the Big_int.big_int_of_string and Num.num_of_string functions also understand these prefixes.

You could also use the Scanf module to parse un-prefixed hexadecimal, decimal, and octal numbers (binary not supported):

# Scanf.sscanf "123459" "%d" (fun x -> x);;
- : int = 123459
# Scanf.sscanf "abcf123" "%x" (fun x -> x);;
- : int = 180154659
# Scanf.sscanf "7651" "%o" (fun x -> x);;
- : int = 4009

Oz[edit]

String.toInt understands the usual prefixes. If a string cannot be parsed, an exception will be thrown.

{String.toInt "42"}         %% decimal
= {String.toInt "0x2a"} %% hexadecimal
= {String.toInt "052"} %% octal
= {String.toInt "0b101010"} %% binary

PARI/GP[edit]

Binary conversion is built in to PARI/GP, this script can convert from bases2-36 to bases 2-36. I've had help with this script at http:\\mersenneforums.org . The main flaw in this script I see is that it doesn't allow 36^x-1 type strings, I'll have to add that on later.

convert(numb1,b1,b2)={
my(B=["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"],a=0,c="");
numb1=Vec(Str(numb1));
forstep(y=#numb1,1,-1,
for(x=1,b1,
if(numb1[y]==B[x],
a=a+(x-1)*b1^(#numb1-y)
)
)
);
until(a/b2==0,
c=concat(B[a%b2+1],c);
a=a\b2
);
c
};

Note that version 2.8.0+ supports hexadecimal (0x1ff) and binary (0b10101) inputs. Further, it can accept generic input as a vector:

Works with: PARI/GP version 2.8.0+
fromdigits([1,15,15],16)

Perl[edit]

The hex() function parses hexadecimal strings. The oct() function parses octal strings, as well as hexadecimal, octal, or binary strings with the appropriate prefix ("0x", "0", and "0b", respectively). There is no need to parse decimal strings because in Perl decimal strings and numbers are interchangeable.

my $dec = "0123459";
my $hex_noprefix = "abcf123";
my $hex_withprefix = "0xabcf123";
my $oct_noprefix = "7651";
my $oct_withprefix = "07651";
my $bin_withprefix = "0b101011001";
 
print 0 + $dec, "\n"; # => 123459
print hex($hex_noprefix), "\n"; # => 180154659
print hex($hex_withprefix), "\n"; # => 180154659
print oct($hex_withprefix), "\n"; # => 180154659
print oct($oct_noprefix), "\n"; # => 4009
print oct($oct_withprefix), "\n"; # => 4009
print oct($bin_withprefix), "\n"; # => 345
# nothing for binary without prefix

Perl 6[edit]

By default, all strings of digits are parsed as base 10 numbers, including those with a leading zero. Numbers with a prefix 0b, 0o, 0d or 0x are parsed as binary, octal, decimal or hexadecimal respectively.

say 0b11011;  # -> 27
say 0o11011; # -> 4617
say 0d11011; # -> 11011
say 0x11011; # -> 69649

Additionally, there are built-in adverbial prefix operators to parse strings of "digits" of radix 2 through radix 36 into decimal. They will fail with a runtime error if they are fed a digit that is not valid in that radix.

my $n = '11011';
 
say :2($n); # -> 27
say :3($n); # -> 112
say :4($n); # -> 325
say :5($n); # -> 756
say :6($n); # -> 1519
say :7($n); # -> 2752
say :8($n); # -> 4617
say :9($n); # -> 7300
say :10($n); # -> 11011
say :11($n); # -> 15984
say :12($n); # -> 22477
say :13($n); # -> 30772
say :14($n); # -> 41175
say :15($n); # -> 54016
say :16($n); # -> 69649
say :17($n); # -> 88452
say :18($n); # -> 110827
say :19($n); # -> 137200
say :20($n); # -> 168021
say :21($n); # -> 203764
say :22($n); # -> 244927
say :23($n); # -> 292032
say :24($n); # -> 345625
say :25($n); # -> 406276
say :26($n); # -> 474579
say :27($n); # -> 551152
say :28($n); # -> 636637
say :29($n); # -> 731700
say :30($n); # -> 837031
say :31($n); # -> 953344
say :32($n); # -> 1081377
say :33($n); # -> 1221892
say :34($n); # -> 1375675
say :35($n); # -> 1543536
say :36($n); # -> 1726309

Phix[edit]

?scanf("1234","%d")
?scanf("0b10101010","%d")
?scanf("#ABCD","%d")
?scanf("#FFFFFFFF","%f")
?scanf("0xFFFFFFFF","%f")
?scanf("0o377","%o")
Output:
{{1234}}
{{170}}
{{43981}}
{{4294967295}}
{{4294967295}}
{{255}}

Note the need for %f (if you want to get an atom rather than an integer back), and double braces (it's a list of potentially several different possible result sets/interpretations), and that scanf() works best with a few literals (esp spaces but most certainly not radix prefixes) in the format string. Finally note that while you can use "#DEADBEEF" (without the quotes, ie a fairly big hex number) in a source code file, the compiler will choke on "DEADBEEF", and likewise so too will scanf(), and the only way round that is to insert the right prefix at the right place.

PHP[edit]

The hexdec(), octdec(), bindec() function parses hexadecimal, octal, and binary strings, respectively. They skip any invalid characters, so a prefix will be ignored. There is no need to parse decimal strings because in PHP decimal strings and numbers are interchangeable.

<?php
echo +"0123459", "\n"; // prints 123459
echo intval("0123459"), "\n"; // prints 123459
echo hexdec("abcf123"), "\n"; // prints 180154659
echo octdec("7651"), "\n"; // prints 4009
echo bindec("101011001"), "\n"; // prints 345
?>

An undocumented feature of intval() is that it can parse prefixed strings when given the base 0:

<?php
echo intval("123459", 0), "\n"; // prints 123459
echo intval("0xabcf123", 0), "\n"; // prints 180154659
echo intval("07651", 0), "\n"; // prints 4009
?>

In addition, for hexadecimals, if you have a "0x"-prefixed string, you can just use it in a numeric operation, and it gets converted to the number automatically:

<?php
echo +"0xabcf123", "\n"; // prints 180154659
# This does not work for octals, however:
echo +"07651", "\n"; // prints 7651
?>

PL/I[edit]

declare N fixed binary;
get edit (N) (A(7)); /* decimal input of 7 columns */
put skip list (N);
 
declare BS bit (32);
get edit (BS) (B(32)); /* Binary input of 32 binary digits. */
put skip edit (BS) (B);
       23 
11010101010111111110000000011101

PicoLisp[edit]

(de parseNumber (S Base)
(let N 0
(for C (chop S)
(when (> (setq C (- (char C) `(char "0"))) 9)
(dec 'C 39) )
(setq N (+ C (* N Base))) )
N ) )
 
(println (parseNumber "91g5dcg2h6da7260a9f3c4a" 19))

Output:

123456789012345678901234567890

PowerShell[edit]

PowerShell parses an integer prefixed with "0x" as hexadecimal. Binary and Octal conversions must use the .NET [Convert]. Here follows a (verbose) example:

 
function Select-NumberFromString
{
[CmdletBinding(DefaultParameterSetName="Decimal")]
[OutputType([PSCustomObject])]
Param
(
[Parameter(Mandatory=$true,
ValueFromPipeline=$true,
ValueFromPipelineByPropertyName=$true,
Position=0)]
[string]
$InputObject,
 
[Parameter(ParameterSetName="Decimal")]
[Alias("d","Dec")]
[switch]
$Decimal,
 
[Parameter(ParameterSetName="Hexadecimal")]
[Alias("h","Hex")]
[switch]
$Hexadecimal,
 
[Parameter(ParameterSetName="Octal")]
[Alias("o","Oct")]
[switch]
$Octal,
 
[Parameter(ParameterSetName="Binary")]
[Alias("b","Bin")]
[switch]
$Binary
)
 
Begin
{
switch ($PSCmdlet.ParameterSetName)
{
"Decimal" {$base = 10; $pattern = '[+-]?\b[0-9]+\b'; break}
"Hexadecimal" {$base = 16; $pattern = '\b[0-9A-F]+\b'  ; break}
"Octal" {$base = 8; $pattern = '\b[0-7]+\b'  ; break}
"Binary" {$base = 2; $pattern = '\b[01]+\b'  ; break}
"Default" {$base = 10; $pattern = '[+-]?\b[0-9]+\b'; break}
}
}
Process
{
foreach ($object in $InputObject)
{
if ($object -match $pattern)
{
$string = $Matches[0]
}
else
{
$string = $null
}
 
 
try
{
$value = [Convert]::ToInt32($string, $base)
}
catch
{
$value = $null
}
 
[PSCustomObject]@{
Number = $value
String = $string
Base = $base
IsNumber = $value -is [int]
InputString = $object
}
 
}
}
}
 

Using a pretend file:

 
$file = @'
John Doe abc1 K2hdystkrs
Jane Doe xyz2 Ew3jtdkufy
Joe Blow def3 Ouy1ttluyl
'
@ -split [Environment]::NewLine
 
$file | Select-NumberFromString -Hexadecimal | Format-Table
 
Output:
Number String Base IsNumber InputString             
------ ------ ---- -------- -----------             
 43969 abc1     16     True John Doe abc1 K2hdystkrs
                16    False Jane Doe xyz2 Ew3jtdkufy
 57075 def3     16     True Joe Blow def3 Ouy1ttluyl

PureBasic[edit]

  ;Val() parses integer strings
; decimal numbers have no prefix, hexadecimal needs a prefix of '$', binary needs a prefix of '%'
Val("1024102410241024") ; => 1024102410241024
Val("$10FFFFFFFF") ; => 73014444031
Val("%1000") ; => 8

Python[edit]

The int function will interpret strings as numbers expressed to some base:

>>> text = '100'
>>> for base in range(2,21):
print ("String '%s' in base %i is  %i in base 10"
 % (text, base, int(text, base)))
 
 
String '100' in base 2 is 4 in base 10
String '100' in base 3 is 9 in base 10
String '100' in base 4 is 16 in base 10
String '100' in base 5 is 25 in base 10
String '100' in base 6 is 36 in base 10
String '100' in base 7 is 49 in base 10
String '100' in base 8 is 64 in base 10
String '100' in base 9 is 81 in base 10
String '100' in base 10 is 100 in base 10
String '100' in base 11 is 121 in base 10
String '100' in base 12 is 144 in base 10
String '100' in base 13 is 169 in base 10
String '100' in base 14 is 196 in base 10
String '100' in base 15 is 225 in base 10
String '100' in base 16 is 256 in base 10
String '100' in base 17 is 289 in base 10
String '100' in base 18 is 324 in base 10
String '100' in base 19 is 361 in base 10
String '100' in base 20 is 400 in base 10

In addition, if you give a base of 0, it will try to figure out the base from the prefix, with the same syntax as a numeric literal in Python:

Python 3.x and 2.6:

>>> int("123459", 0)
123459
>>> int("0xabcf123", 0)
180154659
>>> int("0o7651", 0)
4009
>>> int("0b101011001", 0)
345

Python 2.x:

>>> int("123459", 0)
123459
>>> int("0xabcf123", 0)
180154659
>>> int("07651", 0)
4009

Python 2.6 supports both the above formats, because it supports both types of literals.

R[edit]

# parse a string to decimal
as.numeric("20") # 20
# parse a hex-string to decimal
as.numeric("0x20") # 32
# parse a string to hexadecimal
as.hexmode(as.numeric("32")) # "20"
# parse a string to octal
as.octmode(as.numeric("20")) # "24"

Racket[edit]

 
#lang racket
 
;; Number literals can use #x, #o, and #b for different radices
(list 123 #x7B #o173 #b1111011)
;; -> '(123 123 123 123)
 
;; Explicit conversion of strings can use any radix up to 16
(list (string->number "123")
(string->number "123" 10)
(string->number "7B" 16)
(string->number "83" 15)
(string->number "96" 13)
(string->number "173" 8)
(string->number "11120" 3)
(string->number "1111011" 2))
;; -> '(123 123 123 123 123 123 123 123)
 

REXX[edit]

  ╔══════════════════════════════════════════════════════════════════════════════════╗
  ║ In REXX, there are no  numeric-type  variables  (integer, float, real, unsigned, ║
  ║ logical, binary, complex, double, etc),  only  character.   Everything is stored ║
  ║ as a character string.   Arithmetic is done almost exactly the way a schoolchild ║
  ║ would perform it.  Putting it simply,  to add,  align the two numbers up  (right ║
  ║ justified, with the decimal being the pivot)  and add the columns up, adding the ║
  ║ carries and honoring the signs.                                                  ║
  ║                                                                                  ║
  ║ Multiplications and divisions are similarly performed.                           ║
  ╚══════════════════════════════════════════════════════════════════════════════════╝
/*REXX program demonstrates REXX's ability to handle non-decimal radices*/
a=123 /*all of these assignments are identical: */
b='123'
c='1' || "2" || '3'
d= 1 || 2 || 3
e= 12 || 3
f=120 + 3
g=substr(9912388,3,3)
h=left(123456,3)
i=right(777.123,3)
j=120 + ' 3 '
k=0000000123.0000/1 /*division "normalizes the number (──► 123)*/
 
/*parsing of a decimal number is no */
/*different then parsing a character string*/
/*because decimal numbers ARE character */
/*strings. As such, numbers may have */
/*leading and/or trailing blanks, and in */
/*some cases, imbedded blanks (after any */
/*leading sign). */
 
aa=' 123 ' /*AA's exact value is different the A, */
/*but it's numerically equal to A. */
bb=123. /*the same can be said for the rest of 'em.*/
cc=+123
dd=' + 123'
ee=0000123
ff=1.23e+1
gg=001.23E0002
hh=1230e-1
ii=122.999999999999999999999999999999999 /*assuming NUMERIC DIGITS 9 */
jj= +++123
kk= - -123
 
bingoA='10101'b /*stores a binary value. */
bingoB='10101'B /* B can be uppercase. */
bingoC='1 0101'b /*apostrophes may be used*/
bingoD="1 0101"b /*quotes may be used. */
 
hyoidA='deadbeaf'x /*stores a hexadecimal value.*/
hyoidB="deadbeaf"X
hyoidC='dead beaf'X
hyoidD='de ad be af'X
hyoidE='dead be af'X
hyoidF='7abc'x
/*REXX has several built-in functions */
/*(BIFs) to handle conversions of the */
/*above-mentioned "number" formats. */
 
cyanA=d2x(a) /*converts a decimal string to hexadecimal*/
cyanB=d2x(5612) /*converts a decimal string to hexadecimal*/
 
cyanD=b2x(101101) /*converts a binary string to hexadecimal*/
 
cyanE=b2c(101101) /*some REXXes support this, others don't. */
cyanF=c2b('copernicium') /*some REXXes support this, others don't. */
 
cyanG=c2d('nilla') /*converts a character string to decimal. */
cyanH=d2c(251) /*converts a decimal number to character. */
 
cyanI=x2d(fab) /*converts a hexadecimal string to decimal*/
cyanJ=x2c(fab) /*converts a hexadecimal string to chars. */
cyanK=x2b(fab) /*converts a hexadecimal string to binary.*/
 
befog=d2b(144) /*there's no dec──►binary, but see below.*/
unfog=b2d(101) /*there's no bin──►decimal, but see below.*/
 
do j=0 to 27 /*show some simple low-value conversions. */
say right(j,2) 'in decimal is' d2b(j) "in binary and" d2x(j) 'in hex.'
end /*j*/
exit /*stick a fork in it, we're done.*/
/*────────────────────────────add these subroutines to end─of─program. */
d2b: return word(strip(x2b(d2x(arg(1))),'L',0) 0,1) /*convert dec──►bin*/
b2d: return x2d(b2x(arg(1))) /*convert bin──►dec*/
b2c: return x2c(b2x(arg(1))) /*convert bin──►chr*/
c2b: return word(strip(x2b(c2x(arg(1))),'L',0) 0,1) /*convert chr──►bin*/

Ring[edit]

 
see number("0") + nl
see number("123456789") + nl
see number("-987654321") + nl
 

Output:

0
123456789
-987654321

Ruby[edit]

The String class has methods to coerce a string into another form:

dec1 = "0123459"
hex2 = "abcf123"
oct3 = "7651"
bin4 = "101011001"
 
p dec1.to_i # => 123459
p hex2.hex # => 180154659
p oct3.oct # => 4009
# nothing for binary

The String class has to_i(base) method ( base : 2 .. 36 ). Invalid characters past the end of a valid number are ignored. (This method never raises an exception when base is valid.)

p dec1.to_i(10)         # => 123459
p hex2.to_i(16) # => 180154659
p oct3.to_i(8) # => 4009
p bin4.to_i(2) # => 345
p "xyz9".to_i(10) # => 0 If there is not a valid letter, 0 is returned.

The Integer() method can parse a string, provided the string has the right prefix:

p ((Integer(dec1) rescue nil)) # => ArgumentError: invalid value for Integer: "0123459"
p Integer(dec1.sub(/^0+/,"")) # => 123459
p Integer("0d" + dec1) # => 123459
p Integer("0x" + hex2) # => 180154659
p Integer("0" + oct3) # => 4009
p Integer("0o" + oct3) # => 4009
p Integer("0b" + bin4) # => 345

So can the .to_i(0) method, which never raises an exception:

p dec1.to_i(0)      # => 5349 (which is 12345 in octal, the 9 is discarded)
p ("0d" + dec1).to_i(0) # => 123459
p ("0x" + hex2).to_i(0) # => 180154659
p ("0" + oct3).to_i(0) # => 4009
p ("0o" + oct3).to_i(0) # => 4009
p ("0b" + bin4).to_i(0) # => 345

And then there's the poorly documented Scanf module in the Ruby stdlib, that seems to wrap the matched value in an array:

require 'scanf'
p dec1.scanf("%d") # => [123459]
p hex2.scanf("%x") # => [180154659]
p oct3.scanf("%o") # => [4009]
# no scanf specifier for binary numbers.

Scheme[edit]

> (string->number "abcf123" 16) ; hex
180154659
> (string->number "123459" 10) ; decimal, the "10" is optional
123459
> (string->number "7651" 8) ; octal
4009
> (string->number "101011001" 2) ; binary
345

Seed7[edit]

The function integer(str, radix) converts a numeric string, with a specified radix, to an integer.

$ include "seed7_05.s7i";
 
const proc: main is func
begin
writeln(integer("0123459", 10));
writeln(integer("abcf123", 16));
writeln(integer("7651", 8));
writeln(integer("1010011010", 2));
writeln(integer("tplig0", 32));
writeln(integer("gc0uy9", 36));
end func;
Output:
123459
180154659
4009
666
1000000000
987654321

Sidef[edit]

var dec            = '0123459';
var hex_noprefix = 'abcf123';
var hex_withprefix = '0xabcf123';
var oct_noprefix = '7651';
var oct_withprefix = '07651';
var bin_noprefix = '101011001';
var bin_withprefix = '0b101011001';
 
say dec.num; # => 123459
say hex_noprefix.hex; # => 180154659
say hex_withprefix.hex; # => 180154659
say oct_noprefix.oct; # => 4009
say oct_withprefix.oct; # => 4009
say bin_noprefix.bin; # => 345
say bin_withprefix.bin; # => 345

Standard ML[edit]

- Int.fromString "0123459";
val it = SOME 123459 : int option
- StringCvt.scanString (Int.scan StringCvt.HEX) "0xabcf123";
val it = SOME 180154659 : int option
- StringCvt.scanString (Int.scan StringCvt.HEX) "abcf123";
val it = SOME 180154659 : int option
- StringCvt.scanString (Int.scan StringCvt.OCT) "7651";
val it = SOME 4009 : int option
- StringCvt.scanString (Int.scan StringCvt.BIN) "101011001";
val it = SOME 345 : int option

Tcl[edit]

package require Tcl 8.6;  # For easy scanning of binary
 
# The strings to parse
set dec1 "0123459"
set hex2 "abcf123"
set oct3 "7651"
set bin4 "101011001"
 
# Parse the numbers
scan $dec1 "%d" v1
scan $hex2 "%x" v2
scan $oct3 "%o" v3
scan $bin4 "%b" v4; # Only 8.6-specific operation; others work in all versions
 
# Print out what happened
puts "$dec1->$v1 $hex2->$v2 $oct3->$v3 $bin4->$v4"

This produces this output:

0123459->123459 abcf123->180154659 7651->4009 101011001->345

For a general parser up to base 36, a little function can be written:

proc scanbase {str base} {
set res 0
set digits {0 1 2 3 4 5 6 7 8 9 a b c d e f g h i j k l m n o p q r s t u v w x y z}
foreach char [split [string tolower $str] ""] {
set value [lsearch [lrange $digits 0 [expr {$base - 1}]] $char]
if {$value < 0} {error "bad digit $char"}
set res [expr {$res*$base + $value}]
}
return $res
}

Example:

% scanbase 255 19
822
% scanbase $dec1 8
bad digit 9

XPL0[edit]

include c:\cxpl\codes;
int N; real R;
[Text(8, "123_456");
N:= IntIn(8);
IntOut(0, N); CrLf(0);
Text(8, "ABcd12");
N:= HexIn(8);
HexOut(0, N); CrLf(0);
Text(8, "-3.14159e3");
R:= RlIn(8);
RlOut(0, R); CrLf(0);
]
Output:
123456
00ABCD12
-3141.59000

zkl[edit]

The compiler knows numbers like 0x123, 0b1|101, 0d1_000 but the number conversion functions don't.

fcn b2b(base){
ns:=[20..30].pump(List,T("toString",base));
ns.println();
ns.pump(List,T("toInt",base)).println("\n")
}
b2b(2); b2b(10); b2b(16); b2b(19);

Print 20 .. 30 in binary, decimal, hex & base 19 (or any base 2 .. 32) and parse them to decimal:

Output:
L("10100","10101","10110","10111","11000","11001","11010","11011","11100","11101","11110")
L(20,21,22,23,24,25,26,27,28,29,30)

L("20","21","22","23","24","25","26","27","28","29","30")
L(20,21,22,23,24,25,26,27,28,29,30)

L("14","15","16","17","18","19","1a","1b","1c","1d","1e")
L(20,21,22,23,24,25,26,27,28,29,30)

L("11","12","13","14","15","16","17","18","19","1a","1b")
L(20,21,22,23,24,25,26,27,28,29,30)