x
 
<!DOCTYPE html>
<html>
<body>
<h1>JavaScript SetTimeout()</h1>
<p>等待 3 秒(3000 毫秒)让此页面发生变化。</p>
<h1 id="demo"></h1>
<script>
setTimeout(function() { myFunction("I love You !!!"); }, 3000);
function myFunction(value) {
  document.getElementById("demo").innerHTML = value;
}
</script>
</body>
</html>