SWAP statement

Purpose | Exchange the values of two variables of the same data type.
Syntax | SWAP var1, var2

Remarks

var1 and var2 are two variables of the same type. If you try to swap variables of differing types (for example, string and numeric, or Single-precision and Double-precision), a compile-time Error 482 occurs ("Data type mismatch").

SWAP is handy because a simple trading of values in two consecutive assignment statements does not get the job done:

a = b

b = a

By the time you make the second assignment, variable a does not contain the value it used to. To do this without the SWAP statement requires a temporary variable and a third assignment:

temp = a

a = b

b = temp

SWAP can be used to swap the target values of pointers. In addition, SWAP can also be used to swap the values of pointers themselves.