Expression operator precedence

Apama Documentation : Developing Apama Applications : EPL Reference : Expressions : Expression operator precedence

The following table lists the primary and bitwise expression operators in order by their precedence, from lowest to highest. See also Event expression operator precedence.

Operation	Operator	Precedence
Logical or bitwise union	or	1
Logical or bitwise exclusive or	xor	2
Logical or bitwise intersection	and	3
Unary logical or bitwise inverse	not	4
Relational	<, <=, >, >=, !=, =	5
Additive	+, –	6
String concatenation	+	6
Multiplicative	*, /, %	7
Unary additive	+, –	8
Name qualifier (dot)	.	9
Object constructor	new	9
Subscript	[ ]	9
Action call	actionName()	10
Parenthesized expression	( )	10
Stream query	from	10
Stream source template	all	10

For clarity, it is strongly recommended to use brackets in expressions. This makes it very easy to understand what an expression means. For example:

(10 * 10) > (9 * 9)

Do not use un-bracketed expressions, except where trivial. The following is equivalent to the above expression and is just about acceptable:

10 * 10 > 9 * 9

It is bad practice, however, to use an expression such as the following as it relies on intimate knowledge of the precedence:

1 + 2 - 3 * 4 / 5 < -1 or 5

Contact Support | Community | Feedback