User Guide

Expressions 79
Operator precedence and evaluation ordering
The order of precedence controls the order in which operators in an expression are evaluated. The
order of precedence is as follows:
Unary +, Unary -
^
*, /
\
MOD
+, -
&
EQ, NEQ, LT, LTE, GT, GTE, CONTAINS, DOES NOT CONTAIN
NOT
AND
OR
XOR
EQV
IMP
To enforce a non-standard order of evaluation, you must parenthesize expressions. For example:
• 6 - 3 * 2 is equal to 0
• (6 - 3) * 2 is equal to 6
You can nest parenthesized expressions. When in doubt about the order in which operators in an
expression will be evaluated, use parentheses to force the order of evaluation.
Using functions as operators
Functions are a form of operator. Because ColdFusion functions return values, you can use
function results as operands. Function arguments are expressions. For example, the following are
valid expressions:
• Rand()
• UCase("This is a text: ") & ToString(123 + 456)
Function syntax
The following table shows function syntax and usage guidelines:
Usage Example
No arguments
Function()
Basic format
Function(Data)
Nested functions
Function1(Function2(Data))
Multiple arguments
Function(Data1, Data2, Data3)
String arguments
Function('This is a demo')
Function("This is a demo")
Arguments that are expressions
Function1(X*Y, Function2("Text"))