<!DOCTYPE HTML> <meta charset=utf-8> <title>previousElementSibling</title> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <h1>Test of previousElementSibling</h1> <div id="log"></div> <p id="parentEl">The result of <span id="first_element_child">this test</span> is <span id="middle_element_child" style="font-weight:bold;">unknown.</span> <span id="last_element_child" style="display:none;">fnord</span> </p> <script> test(function() { var parentEl = document.getElementById("parentEl"); var lec = document.getElementById("last_element_child"); var pes = lec.previousElementSibling; assert_true(!!pes) assert_equals(pes.nodeType, 1) assert_equals(pes.getAttribute("id"), "middle_element_child") }) </script>