Equal to (==)
The ==
operator
checks for equality of two expressions or for two record variables.
Syntax 1: Expression comparison
expr == expr
- expr can be any expression supported by the language.
Syntax 2: Record comparison
record1.* == record2.*
- record1 and record2 are records with the same structure.
Usage
The ==
operator evaluates
whether two expressions or two records are identical.
A single
equal sign (=
) can be used as an alias for the ==
operator.
The syntax comparing two expressions applies to most data types, except complex types like BYTE
and TEXT
.
When comparing simple expressions (expr ==
expr
), the result of the operator is NULL
when one of
the operands is NULL
.
When comparing two records using the second syntax,
the runtime system compares all corresponding members of the records. If a pair of members are
different, the result of the operator is FALSE
. When two corresponding members are
NULL
, they are considered as equal. This second syntax allows you to compare all
members of records, but records must have the same structure.
Example
MAIN
DEFINE n INTEGER
LET n=512
IF n==512 THEN
DISPLAY "The variable equals 512."
END IF
END MAIN