执行一个全局替换, 忽略大小写 - 在线编辑器

          <p>单击按钮将段落中的“blue”替换成“red”。</p>
<p id="demo">Mr Blue has a blue house and a blue car.</p>
<button onclick="myFunction()">点我</button>
<script>
  function myFunction() {
    var str = document.getElementById("demo").innerHTML;
    var n = str.replace(/blue/gi, "red");
    document.getElementById("demo").innerHTML = n;
  }
</script>
        