u-val>TypeError</emu-val> exception.</li><li>Return <var>accumulator</var>.</li></ol></emu-alg></emu-import>
        </emu-clause>

        <emu-clause id="Set.prototype.join">
            <h1><span class="secnum">2.7</span> Set.prototype.join( [ <var>separator</var> ] )</h1>
            <emu-import href="./set/prototype-join.html"><p>When the <code>join</code> method is called, the following steps are taken:</p><emu-alg><ol><li>Let <var>set</var> be the <emu-val>this</emu-val> value.<ol><li>If Type(<var>se