</li></ol></li><li>Return <emu-val>undefined</emu-val>.

</li></ol></emu-alg></emu-import>
        </emu-clause>

        <emu-clause id="Map.prototype.keyOf">
            <h1><span class="secnum">3.6</span> Map.prototype.keyOf( <var>searchElement</var> )</h1>
            <emu-import href="./map/prototype-key-of.html"><p>When the <code>keyOf</code> method is called, the following steps are taken:</p><emu-alg><ol><li>Let <var>map</var> be the <emu-val>this</emu-val> value.<ol><li>If Type(<var>map</var>) is n