ZUML Reference/EL Expressions/Operators

EL expressions provide the following operators:

Type	Operators	Description
Arithmetic	+, -, *, /, div, %, mod, -	/ and div are the same, while % and mod are the same.
Logical	and, &&, or, ||, not, !, empty	The empty operator is a prefix operation that can be used to determine whether a value is null or empty, such as ${empty foo}.
Relational	==, eq, !=, ne, <, lt, >, gt, <=, ge, >=, le	Comparisons can be made against other values, or against boolean, string, integer, or floating point literals.
Conditional	A ? B : C	It evaluate B or C, depending on the result of the evaluation of A.
Index	[]	To evaluate expr-a[expr-b], evaluate expr-a into value-a and evaluate expr-b into value-b. If either value-a or value-b is null, return null. If value-a is a Map, return value-a.get(value-b). If !value-a.containsKey(value-b), then return null. If value-a is a List or array, coerce value-b to int and return value-a.get(value-b) or Array.get(value-a, value-b), as appropriate. If the coercion couldn't be performed, an error is returned. If the get call returns an IndexOutOfBoundsException, null is returned. If the get call returns another exception, an error is returned. If value-a is a JavaBeans object, coerce value-b to String. If value-b is a readable property of value-a, then return the result of a get call. If the get method throws an exception, an error is returned.
Member	.	Properties of variables are accessed using the . operator and can be nested arbitrarily. The value of a map can be accessed by using the . operator.

---

The relative precedence levels of operators from the highest to lowest, left to right are as follows:

• [] .
• ()
• - not ! empty
• * / div % mod
• + -
• < > <= >= lt gt le ge
• == != eq ne
• && and
• || or
• ? :

---

Version History

Version	Date	Content