if
| Stack | Position | Description |
|---|---|---|
| Stack(In) | top | value |
| Stack(Out) | top | - |
Stack top value will be converted into { TRUE, FALSE }:
| empty stack | FALSE |
| numeric value= 0 | FALSE |
| numeric value != 0 | TRUE |
| empty variable (INVALID) | FALSE |
| object | TRUE |
| ZERO object | FALSE |
| other value | TRUE |
The following statement (statement group) will be executed for TRUE and skipped for FALSE. As shown in the table, a variable with no assigned value provides FALSE.
Information: if- or if-else constructions can have a nesting depth of up to 37.