/Reference/Global_Objects/Array">Array</a>[<a class="qm-api-type-link" href="https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object">Object</a>] / <a class="qm-api-type-link" href="https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object">Object</a></span></span></span><span class="qm-api-javascript-header-function-arg qm-api-optional"><span class="qm-api-javascript-header-function-arg-name">key</span><span class="qm-api-javascript-header-function-arg-type