js的数组申明

 //数组的3种申明方法,如下example

 //数组是一种object类型 通过typeof 来检查

 //example 1

 var arr= new Array("h","k","M","c");

 console.log(typeof arr);//object

 for( var i in arr){

     console.log(arr[i]);

 }

 //example 2

 var arr1=Array("hello","你好","大海");

 console.log(typeof arr1);//object

 for( var i in arr1){

     console.log(arr1[i]);

 }

 //example 3

 var arr3=["hello","你好","大海"];

 console.log(typeof arr3);//object

 for(var i in arr3){

     console.log(arr3[i]);

 }

 //example 二维数组

 var arr4=["hello","你好","大海"]

     arr4[]=['这是哪里'];

     console.log(arr4[][]);