数组之splice()和slice()
2020-03-16 本文已影响0人
小雪洁
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<meta charset="utf-8">
<title>splice与slice数组中间元素管理</title>
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<script>
//数组截取 arr.slice(index1,index2), 截取范围是[index1,index2)
let a=[1,2,3,4,5];
console.log(a.slice(1));//返回截取的元素
console.log(a);//原数组没有变化
console.log(a.slice(1,4));//[2, 3, 4]
console.log(a.slice());//[1,2,3,4,5]
//arr.splice(index,n,item) 从第index索引开始，截取n个元素，将其替换为item
console.log(a.splice(0,2));//[1,2]splice方法会改变原数组
console.log(a);//[3, 4, 5]
//替换数组中某个元素
let b=[1,2,3,4,5];
let c =b.splice(0,3,"hxj","ydc"); //返回的是[1,2,3]赋给c,而b中被截掉的元素由"hxj","ydc"代替
console.log(b);//["hxj", "ydc", 4, 5]
console.log(c);//[1, 2, 3]
let d=[1,2,3,4,5];
d.splice(2,1,"hxj");//将索引2的元素替换为"hxj"
console.log(d);//[1, 2, "hxj", 4, 5]
//往数组中任何一个位置增加元素
let e=[1,2,3,4,5];
e.splice(1,0,"hxj","ydc");
console.log(e);//[1, "hxj", "ydc", 2, 3, 4, 5]
let f=[1,2,3,4,5];
//f.splice(f.length,0,"hxj");
f.splice(0,0,"hxj");//["hxj", 1, 2, 3, 4, 5]
console.log(f);
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