# `join` The `join` filter returns a string which is the concatenation of the itemsof a sequence: <table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1 2</pre></div></td><td class="code"><div class="highlight"><pre>{{ [1, 2, 3]|join }} {# returns 123 #} </pre></div></td></tr></table> The separator between elements is an empty string per default, but you candefine it with the optional first parameter: <table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1 2</pre></div></td><td class="code"><div class="highlight"><pre>{{ [1, 2, 3]|join('|') }} {# outputs 1|2|3 #} </pre></div></td></tr></table> ### Arguments - `glue`: The separator