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}
:
<html>
<body>
Hello ${params.name}
</body>
</html>
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.