replace() 方法将接收字符串作为参数

<p>替换 "Microsoft" 为 "Mifengjc" :</p>

<button onclick="myFunction()">点我</button>

<p id="demo">请访问 Microsoft!</p>

<script>

  function myFunction() {

    var str = document.getElementById("demo").innerHTML;

    var txt = str.replace("Microsoft", "Mifengjc");

    document.getElementById("demo").innerHTML = txt;

  }

</script>