Operators

Expression Language supports a number of standard operators that can operate upon variables, primitive values, or both. Every expression builder on the platform, such as those inside the rules engine, contains a full list of available operators. Several types of available operators are listed here:

Arithmetic Operations

Operator	Use	EL Expression	Result
+	Add	${1.2E4+1.4}	12001.4
-	Subtract or negative value	${-72-8}	-80
*	Multiply	${2.5*10}	25
/ (or) div	Divide	${3 div 4}	0.75
% (or) mod	Modulo (remainder)	${10 mod 4}	2

Logic Operations

Operator	Use	EL Expression	Result
and	Test for logical AND	${2>1 and ;b' > 'c'}	false
or	Test for logical OR	${2>1 or 'b' > 'c'}	true
not (or) !	Unary boolean complement	${!empty param.Add}	False if the request parameter named Add is null or an empty string.

Relational Operations

Operator	Use	EL Expression	Result
= (or) eq	Test for equality	${150.0 == 150}	True
!=(or) ne	Test for inequality	${(10*10) ne 100}	False
< (or) lt	Test for less than	${'a' < 'b'}	True
> (or) gt	Test for greater than	${'hip' gt 'hit'}	False
<== (or) ge	Test for greater than or equal	${3 ge 3}	True
>== (or) le	Test for less than or equal	${4.1 >==3}	True

Empty Operation

Operator	Use	EL Expression	Result
empty	Test for empty value	${!empty param.Add}	False if the request parameter named Add is null or an empty string.

Conditional Operation

This is the equivent of an “if, then, else” statement – the operator requires 3 inputs, a testable condition that results in a Boolean (true or false), where when the condition is true, the variable to the right of the test is applied, if false the third variable is evaluated.

Operator	Use	EL Expression	Result
?:	Ternary operator–(3 inputs). Test for potential outcomes.	${empty field.value ? 1 : field.value +1}	1 if a field.value is empty or field.value + 1.