体验js中splice()的强大(插入、删除或替换数组的元素)

处理数组的方法很多，javascript splice()算是最强大的了，它可以用于插入、删除或替换数组的元素。

Syntax

array.splice(start)
array.splice(start, deleteCount)
array.splice(start, deleteCount, item1, item2, ...)

1.删除-用于删除元素，两个参数，第一个参数（要删除第一项的位置），第二个参数（要删除的项数）

Remove 1 element from index 3
var myFish = ["angel", "clown", "drum", "mandarin", "surgeon"];
var removed = myFish.splice(3, 1);

// removed is ["mandarin"]
// myFish is ["angel", "clown", "drum", "surgeon"]

2.插入-向数组指定位置插入任意项元素。三个参数，第一个参数（其实位置），第二个参数（0），第三个参数（插入的项）

Remove 0 elements from index 2, and insert "drum"
var myFish = ["angel", "clown", "mandarin", "surgeon"];
var removed = myFish.splice(2, 0, "drum");

// myFish is ["angel", "clown", "drum", "mandarin", "surgeon"]
// removed is [], no elements removed

3.替换-向数组指定位置插入任意项元素，同时删除任意数量的项，三个参数。第一个参数（起始位置），第二个参数（删除的项数），第三个参数（插入任意数量的项）

Remove 1 element from index 2, and insert "trumpet"
var myFish = ["angel", "clown", "drum", "surgeon"];
var removed = myFish.splice(2, 1, 'trumpet');

// myFish is ["angel", "clown", "trumpet", "surgeon"]
// removed is ["drum"]