IF operator
The IF
operator - creating a property implementing selection of a value by condition (single form).
Syntax
result IF condition
Description
The IF
operator creates a property that returns the given value when a certain condition is met. If the condition is not met, the property returns NULL
.
Parameters
-
result
Expression whose value defines the result.
-
condition
An expression whose value defines the condition.
Examples
name = DATA STRING[100] (Book);
hasName (Book b) = TRUE IF name(b);
background (Book b) = RGB(224, 255, 128) IF b IS Book;
countTags (Book b) = GROUP SUM 1 IF in(b, Tag t);