转自https://blog.csdn.net/qq_42043377/article/details/83003159
感谢博主分享，真是让人秒懂哇~
其实说白了 vue中的splice和javaScript中的是一样的
splice(index,len,[item])它也可以用来替换/删除/添加数组内某一个或者几个值（该方法会改变原始数组）
index:数组开始下标
len: 替换/删除的长度
item:替换的值，删除操作的话 item为空
举个例子:
在本例中，我们将创建一个新数组，并向其添加一个元素：
<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
arr.splice(2,0,"William")
document.write(arr + "<br />")
</script>
输出:
George,John,Thomas,James,Adrew,Martin
George,John,William,Thomas,James,Adrew,Martin
在本例中我们将删除位于 index 2 的元素，并添加一个新元素来替代被删除的元素：
<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
arr.splice(2,1,"William")
document.write(arr)
</script>
输出：
George,John,Thomas,James,Adrew,Martin
George,John,William,James,Adrew,Martin
在本例中我们将删除从 index 2 (“Thomas”) 开始的三个元素，并添加一个新元素 (“William”) 来替代被删除的元素：
<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
arr.splice(2,3,"William")
document.write(arr)
</script>
输出：
George,John,Thomas,James,Adrew,Martin
George,John,William,Martin
这个例子是删除全部
<script type="text/javascript">
var arr = new Array(6)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"
arr[3] = "James"
arr[4] = "Adrew"
arr[5] = "Martin"
document.write(arr + "<br />")
arr.splice(0,arr.length)
document.write(arr)
</script>
输出:
什么都没有