(Quick Reference)

join

Purpose

Uses the Groovy JDK join method to concatenate the toString() representation of each item in this collection with the given separator.

<g:join in="['Grails', 'Groovy', 'Gradle']" delimiter="_"/>

That would result in output like this:

Grails_Groovy_Gradle

Attributes

in - The collection to iterate over
delimiter (optional) - The value of the delimiter to use during the join. If no delimiter is specified then ", " (a comma followed by a space) will be used