Compound data type

Create a complex data type Point(x,y)

Ada

Tagged Type

Ada tagged types are extensible through inheritance. The reserved word tagged causes the compiler to create a tag for the type. The tag identifies the position of the type in an inheritance hierarchy.

type Point is tagged record
   X : Integer := 0;
   Y : Integer := 0;
end record;

Record Type

Ada record types are not extensible through inheritance. Without the reserved word tagged the record does not belong to an inheritance hierarchy.

type Point is record
   X : Integer := 0;
   Y : Integer := 0;
end record;

Parameterized Types

An Ada record type can contain a discriminant. The discriminant is used to choose between internal structural representations. Parameterized types were introduced to Ada before tagged types. Inheritance is generally a cleaner solution to multiple representations than is a parameterized type.

type Person (Gender : Gender_Type) is record
   Name   : Name_String;
   Age    : Natural;
   Weight : Float;
   Case Gender is
      when Male =>
         Beard_Length : Float;
      when Female =>
         null;
   end case;
end record;

In this case every person will have the attributes of gender, name, age, and weight. A person with a Male gender will also have a beard length.

BASIC

Interpeter: QuickBasic 4.5, PB 7.1

TYPE Point
  x AS INTEGER
  y AS INTEGER
END TYPE

C

Compiler: GCC, MSVC, BCC, Watcom

Libraries: Standard

 typedef struct Point
 {
   int x;
   int y;
 } Point;

C++

Compiler: GCC, Visual C++, BCC, Watcom

 struct Point
 {
   int x;
   int y;
 };

It is also possible to add a constructor (this allows the use of Point(x, y) in expressions):

 struct Point
 {
   int x;
   int y;
   Point(int ax, int ay): x(ax), y(ax) {}
 };

Point can also be parametrized on the coordinate type:

 template<typename Coordinate> struct point
 {
   Coordinate x, y;
 };
 
 // A point with integer coordinates
 Point<int> point1 = { 3, 5 };
 
 // a point with floating point coordinates
 Point<float> point2 = { 1.7, 3.6 };

Of course, a constructor can be added in this case as well.

C#

 struct Point
 {
   public int x, y;
   public Point(int x, int y) {
     this.x = x;
     this.y = y;
   }
 }

IDL

point = {x: 6 , y: 0 } 
point.y = 7
print, point
;=> {       6       7}

Java

// The byte structure format does not exist natively --> TODO.
public class Point
{
  public int x, y;
  public Point() { this(0); }
  public Point(int x0) { this(x0,0); }
  public Point(int x0, int y0) { x = x0; y = y0; }

  public static void main(String args[])
  {
    Point point = new Point(1,2);
    System.out.println("x = " + point.x );
    System.out.println("y = " + point.y );
  }
}

JavaScript

 var point = new Object();
 point.x = 1;
 point.y = 2;

JSON

 var point = {
   x:1,
   y:2
 };

PHP

 # Using pack/unpack 
 $point = pack("ii", 1, 2);

 $u = unpack("ix/iy", $point);
 echo $x;
 echo $y;

 list($x,$y) = unpack("ii", $point);
 echo $x;
 echo $y;

Tcl

This appears to be a sub-functionality of a proper associative array:

 array set point {x 4 y 5}
 set point(y) 7
 puts "Point is {$point(x),$point(y)}"
 # => Point is {4,7}

OCaml

 type json point = < x: int; y: int >