深入JS1.2数组

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数组基础

定义
var arr=[1,2,3];

var arr=new Array(1,2,3);

<!DOCTYPE HTML><html><head><meta charset='utf-8'><title>定义数组</title><script>//var arr=[1,2,3];var arr=new Array(1,2,3);alert(arr);</script></head></html>

length的获取和设置

<!DOCTYPE HTML><html><head><meta charset='utf-8'><title>length</title><script>var arr=[1,2,3,4,5];arr.length=4;alert(arr);</script></head></html>

数组基本操作方法

添加：push(尾)，unshift(头)

删除：pop(尾)，shift(头)

替换：删除：splice(起点，长度)，添加：splice(起点，长度0，添加元素)，替换：splice(起点，删除长度，添加元素)

<!DOCTYPE HTML><html><head><meta charset='utf-8'><title>length</title><script>var arr=[1,2,3,4,5];//arr.push(6,7);//arr.pop();//arr.unshift(0);//arr.shift();//arr.splice(2,2);//arr.splice(2,0,'a','b');arr.splice(2,3,'a','b','c','d');alert(arr);</script></head></html>

转换

连接concat

拼接join

<!DOCTYPE HTML><html><head><meta charset='utf-8'><title>length</title><script>var a=[1,2,3];var b=[4,5,6];//alert(a.concat(b));alert(a.join('-'));</script></head></html>

排序sort

<!DOCTYPE HTML><html><head><meta charset='utf-8'><title>length</title><script>var arr=['aedad','sdfs','sdf','dhg','ryur6'];arr.sort();alert(arr);</script></head></html>

<!DOCTYPE HTML><html><head><meta charset='utf-8'><title>length</title><script>var arr=['12','111','3','34'];arr.sort(function (n1,n2){return n1-n2;});alert(arr);</script></head></html>

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