Calling methods
You call methods using a comma-separated list of expressions in parentheses. These expressions are called parameters. The method call passes the parameters to the method, which returns a result. The result is the value of the method call.
For example, assume the method called avg returns an average of its parameters, 3 and 5 in the following example:
${avg(3, 5)}
produces this output:
4
See Method Reference for a list of methods.