grails Expressions


In GSP the <%= %> syntax is rarely used due to the support for GSP expressions.

A GSP expression is similar to a JSP EL expression or a Groovy GString and takes the form ${expr}:

    Hello ${}

However, unlike JSP EL you can have any Groovy expression within the ${..} block.

Any Groovy expression can be interpolated in all string literals, apart from single and triple single quoted strings. Interpolation is the act of replacing a placeholder in the string with its value upon evaluation of the string. The placeholder expressions are surrounded by ${} or prefixed with $ for dotted expressions. The expression value inside the placeholder is evaluated to its string representation when the GString is passed to a method taking a String as argument by calling toString() on that expression.