<p id="demo">点击按钮添加和删除元素</p>

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

<script>

function myFunction(){

    var fruits = ["Banana", "Orange", "Apple", "Mango"];

    fruits.splice(2,1,"Lemon","Kiwi");

    var x=document.getElementById("demo");

    x.innerHTML=fruits;

}

</script>

​