认识 Javascript 数组
作者:郭润桂
1.认识数组....................................................................................................................................................................................1
1.1 定义数组.........................................................................................................................................................................1
1.2 多维数组.........................................................................................................................................................................2
1.3 Array literals...................................................................................................................................................................2
2.数组元素的操作.......................................................................................................................................................................3
2.1 数组的循环.....................................................................................................................................................................3
2.2 数组常用函数.................................................................................................................................................................3
concat............................................................................................................................................................................3
join................................................................................................................................................................................4
pop.................................................................................................................................................................................4
push...............................................................................................................................................................................4
sort.................................................................................................................................................................................5
reverse...........................................................................................................................................................................5
shift...............................................................................................................................................................................5
unshift...........................................................................................................................................................................6
slice...............................................................................................................................................................................6
splice.............................................................................................................................................................................6
toString..........................................................................................................................................................................7
toLocaleString...............................................................................................................................................................8
valueOf..........................................................................................................................................................................8
1.认识数组
数组就是某类数据的集合,数据类型可以是整型、字符串、甚至是对象
Javascript 不支持多维数组,但是因为数组里面可以包含对象(数组也是一个对象),所以数组可以通过相互嵌套
实现类似多维数组的功能
1.1 定义数组
声明有 10 个元素的数组
var a = new Array(10);
此时为 a 已经开辟了内存空间,包含 10 个元素,用数组名称加 [下标] 来调用,例如 alert(a[2])但此时元素并未初始
化,调用将返回 undefined
以下代码定义了个可变数组,并进行赋值
var a = new Array();
a[0] = 10;
a[1] = "aaa";