Boolean Is Equal '==', '==='

The Boolean operator Is Equal compares two operands and returns TRUE (-1) if both values are the same, or returns FALSE (0), otherwise. Is Equal can be used in both variable and constant expressions. Example:

X := Y == Z

The above example compares the value of Y with the value of Z and sets X to either: TRUE (-1) if Y is the same value as Z, or FALSE (0) if Y is not the same value as Z.

This operator is often used in conditional expressions, such as in the following example.

IF (Y == 1)

Here, the Is Equal operator returns TRUE if Y equals 1.

Is Equal has an assignment form, ===, that uses the variable to its left as both the first operand and the result destination. For example,

X === Y     'Short form of X := X == Y

Here, X is compared with Y, and if they are equal, X is set to TRUE (-1), otherwise X is set to FALSE (0). The assignment form of Is Equal may also be used within expressions for intermediate results; see Intermediate Assignments.