1. 定义
- 通过字面量定义数组:
var arr = [ ];
- new Array()定义数组:
var arr1 = new Array [ ];
arr1[0] = 值;
arr1[1] = 值;
2. 属性length
数组的最后一个元素 length-1
3. 数组的循环
- for循环
var arr = ['红色','黄色','蓝色']; for (var i = 0; i <= arr.length; i++) { console.log(arr[i]); }
- for in
for(值 in 数组)
var arr = ['红色','黄色','蓝色']; for ( item in arr ) { console.log(arr[item]); //item就是下标,和上面 for 循环中的 in 是一样的 }
- forEach
var arr = ['红色','黄色','蓝色']; arr.forEach (function( items,index){ console.log(items); //items是值 循环出arr里面的值
console.log(index); //index是下标 })