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Pointer

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== Definition == == Definition ==
-'''POINTER'''+=== Statement ===
 +Declaration of a pointer:<br>
 +<datatype> POINTER <pointername><br>
 +<datatype> * <pointername>
-'''Pointer'''s, are used to point to a location in [[memory]]. It uses 32 [[bit]]s (4 [[byte]]s) so it can map 4GB of memory into bytes. '''Pointer'''s can point to any datatype: [[int]]s, [[short]]s, [[string]]s and even usermade datatypes.+Assignment of a value to the location pointed to:<br>
 +POINTER <pointername> = <value>;<br>
 +<nowiki>*</nowiki> <pointername> = <value>;
 + 
 +=== Concept ===
 +'''Pointer'''s, are used to point to a location in [[memory]]. It uses 32 [[bit]]s (4 [[byte]]s) so it can map 4GB of memory into bytes. '''Pointer'''s can point to any [[datatype]]: [[int]]s, [[short]]s, [[string]]s or even usermade datatypes.
== Example == == Example ==
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say(*my_int_pointer); say(*my_int_pointer);
- Loop+ Repeat
frame; frame;
- End+ Until(key(_esc))
 + 
End End
</pre> </pre>
-The & (offset) operator, when used with pointers, returns a [[void]] pointer to a variable. In the example it returns an int pointer to the variable my_int. The * (pointer) operator, when used with pointers, makes it so the pointer variable is not accessed, but the variable it's pointing to. In the example it changes access from my_int_pointer to my_int.+The & ([[offset]]) operator, when used with pointers, returns a [[void]] pointer to a variable. In the example it returns an int pointer to the variable my_int. The * (pointer) operator, when used with pointers, makes it so the pointer variable is not accessed, but the variable it's pointing to. In the example it changes access from my_int_pointer to my_int.

Revision as of 22:36, 29 May 2007


Contents

Definition

Statement

Declaration of a pointer:
<datatype> POINTER <pointername>
<datatype> * <pointername>

Assignment of a value to the location pointed to:
POINTER <pointername> = <value>;
* <pointername> = <value>;

Concept

Pointers, are used to point to a location in memory. It uses 32 bits (4 bytes) so it can map 4GB of memory into bytes. Pointers can point to any datatype: ints, shorts, strings or even usermade datatypes.

Example

Program pointers;
Private
    int my_int;
    int pointer my_int_pointer;
Begin

    my_int_pointer = &my_int;

    my_int = 3;
    say(my_int);
    say(*my_int_pointer);
  
    *my_int_pointer = 4;
    say(my_int);
    say(*my_int_pointer);

    Repeat
        frame;
    Until(key(_esc))

End

The & (offset) operator, when used with pointers, returns a void pointer to a variable. In the example it returns an int pointer to the variable my_int. The * (pointer) operator, when used with pointers, makes it so the pointer variable is not accessed, but the variable it's pointing to. In the example it changes access from my_int_pointer to my_int.

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