js向数组中插入元素

1、在数组的开头添加新元素 - unshift()

<script>
function myFunction()
{
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.unshift("Lemon","Pineapple");
var x=document.getElementById("demo");
x.innerHTML=fruits;
}
</script>
 

测试结果:

Lemon,Pineapple,Banana,Orange,Apple,Mango

2、在数组的第2位置添加一个元素 - splice()

<script>

function myFunction()

{

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

fruits.splice(2,0,"Lemon","Kiwi");

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

x.innerHTML=fruits;

}

</script>

测试结果:Banana,Orange,Lemon,Kiwi,Apple,Mango

3、数组的末尾添加新的元素 - push()

<script>
var fruits = ["Banana", "Orange", "Apple", "Mango"];
​
function myFunction()
{
fruits.push("Kiwi")
var x=document.getElementById("demo");
x.innerHTML=fruits;
}
</script>
测试结果:Banana,Orange,Apple,Mango,Kiwi
以上文档参考来源：
http://www.jb51.net/article/73867.htm
实际应用：
var head_data = opt.head;//注意，如果有多层嵌套时要分别获取元素的根
var head_icon = head_data.icon;
head_icon.splice(3,0,{
	icon: 'fi fi-clothes',
    title: '主题',
    onclick: function(){
         layer.open({
				  type: 2,
				  title: '切换皮肤',
				  shadeClose: false,
				  shade: 0,
				  area: ['380px', '40%'],
				  content: 'url' //iframe的url
			});
         
    }
});