32 lines
1.8 KiB
Plaintext
32 lines
1.8 KiB
Plaintext
|
\b;Arrays
|
||
|
|
An array is basically a collection of variables of the same type or class. You can use N dimensionnal arrays in the CBOT language. Each dimension is limited to 9999 elements. You must use square brackets \c;[]\n; after the type name or the variable name to declare an array.
|
||
|
|
\c;
|
||
|
|
\s;int [ ] a; // an array of int
|
||
|
|
\s;int a [12]; // an array of int limited to 12 elements
|
||
|
|
\s;string s[3]; // an array of 3 strings
|
||
|
|
\s;float xy[][]; // an 2 dimensionnal array of floats
|
||
|
|
\n;
|
||
|
|
Actually when the CBOT interpreter encounters an array declaration, it just creates a \c;\l;null\u cbot\null;\n; \l;reference\u cbot\pointer;:
|
||
|
|
\c;
|
||
|
|
\s;int a[5]; // a is now a null reference
|
||
|
|
\n;
|
||
|
|
As soon as you put values into the array, the elements are created and the reference is initialized:
|
||
|
|
\c;
|
||
|
|
\s;a[2] = 213; // a points to
|
||
|
|
\s; // 3 élements [0], [1] et [2]
|
||
|
|
\n;
|
||
|
|
After this operation, \c;a\n; contains a reference to the elements of the array. Elements \c;[0]\n; and \c;[1]\n; are created but not initialized because an array cannot contain empty elements. The \c;\l;sizeof\u cbot\sizeof;\n; instruction allows you to obtain the number of elements contained in an array.
|
||
|
|
|
||
|
|
When an array is declared with a maximum size, the program will stop as soon as there is an access beyond the maximum array size. No error is signalled during compilation even if the error is obvious:
|
||
|
|
\c;
|
||
|
|
\s;{
|
||
|
|
\s; int a[5];
|
||
|
|
\s; a[7] = 123; // no error at compile time
|
||
|
|
\s; // but error at run time
|
||
|
|
\s;}
|
||
|
|
\n;
|
||
|
|
If you pass an array as parameter to a \l;function\u cbot\function;, the function only receives a \l;reference\u cbot\pointer; to the array. That means if you modify an array element in the function, the element of the array that has been passed the function will be actuallay modified.
|
||
|
|
|
||
|
|
\t;See also
|
||
|
|
\l;Programming\u cbot;, \l;types\u cbot\type; and \l;categories\u cbot\category;.
|