Summary

Tests whether an expression can be cast into a referenced type. This keyword is used in any expression.

Syntax

[?var:] className (expression instanceof type) 

Description

The instanceof operator can be used in the condition part or in the action part of a rule and in a function. It tests whether the passed expression (left operand of instanceof) can be cast into the passed type (right operand of instanceof) without raising a ClassCastException. If it passed successfully, this test returns true. It returns false if the test is unsuccessful.

Example

rule InstanceofTest {
   when {
      ?a: Alarm(equipment instanceof Multiplex);
   }
   then {
      System.out.println("Alarm occurs on Multiplex");
   }
};

See Also