<html>
<body>
搜索: <input type="search" id="mySearch" value="Food">
<p>点击按钮修改过搜索字段的 value 属性值。</p>
<button onclick="myFunction()">点我</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("mySearch").value = "Muscle Cars";
}
</script>
</body>
</html>