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JavaScript高级程序设计:本地对象Array

栏目: 网页设计 / 发布于: / 人气:2.44W

创建Array对象

JavaScript高级程序设计:本地对象Array

复制代码 代码如下:

//one

var aValues=new Array();

//two

var aValues=new Array(20);

//three

var aColors=new Array();

aColors[0]="red";

aColors[1]="green";

aColors[2]="blue";

//four

var aColors=new Array("red","green","blue");

//five

var aColors=["red","green","blue"];

join && split

join:连接字符串

复制代码 代码如下:

var aColors=["red","green","blue"];

alert((","));//outputs "red,green,blue"

alert(("-spring-"));//outputs "red-spring-green-spring-blue"

alert(("]["));//outputs "red][green][blue"

split:分拆字符串

复制代码 代码如下:

var sColors="red,green,blue";

var aColors=t(",");//outputs ["red", "green", "blue"]

var redColors=aColors[0]t("");//outputs ["r", "e", "d"]

concat && slice

concat:追加数组

复制代码 代码如下:

var aColors=["red","green","blue"];

var aColors2=at("yellow","purple");

alert(aColors);//outputs ["red", "green", "blue"]

alert(aColors2);//outputs ["red", "green", "blue", "yellow", "purple"]

slice:返回具有特定项的新数组

复制代码 代码如下:

var aColors=["red","green","blue","yellow","purple"];

var aColors2=e(1);//outputs ["green","blue","yellow","purple"]

var aColors3=e(1,4);//outputs ["green","blue","yellow"]

push && pop

跟栈一样,Array提供了push和pop方法,push方法用于在Array结尾添加一个或多个项,pop用于删除最后一个数组项,返回它作为函数值

复制代码 代码如下:

var stack=new Array;

("red");

("green");

("blue");

alert(stack);//outputs ["red","green","blue"]

var vItem=();

alert(vItem);//outputs ["blue"]

alert(stack);//otputs ["red","green"]

shift && unshift

shift:删除数组中第一项,将其作为函数返回值,unshift:把一个项放在数组的第一个位置,然后把余下的项向下移动一个位置

复制代码 代码如下:

var aColors=["red","green","blue"];

var vItem=t();

alert(aColors);//outputs ["green","blue"]

alert(vItem);//outputs ["red"]

ift("black");

alert(aColors);//outputs ["black","green","blue"]

reverse && sort

reverse:颠倒数组项的顺序,sort:按数组项的值升序排列(首先要调用toString()方法,将所有值转换成字符串)

复制代码 代码如下:

var aColors=["blue","green","red"];

rse();

alert(aColors);//outputs ["red","green","blue"]

();

alert(aColors);//outputs ["blue","green","red"]

注意:

复制代码 代码如下:

var aColors=[3,32,2,5];

();

alert(aColors);//outputs [2,3,32,5]

这是因为数字被转换成字符串,然后按字符代码进行比较的。

splice

splice:把数据项插入数组的中部

1、用作删除:只要声明两个参数,第一个参数为要删除的第一个项的`位置,第二个参数为删除项的个数

复制代码 代码如下:

var aColors=["red","green","blue","yellow"];

ce(0,2);

alert(aColors);//outputs ["blue", "yellow"]

2、用作插入:声明三个或以上参数(第二个参数为0)就可以把数据插入指定位置,第一个参数为地始位置,第二个参数为0,第三个及以上参数为插入项

复制代码 代码如下:

var aColors=["red","green","blue","yellow"];

ce(2,0,"black","white");

alert(aColors);//outputs ["red","green","black","white","blue", "yellow"]

3、用作删除并插入:声明三个或以上参数(第二个参数为不0)就可以把数据插入指定位置,第一个参数为地始位置,第二个参数为要删除的项的个数,第三个及以上参数为插入项

复制代码 代码如下:

var aColors=["red","green","blue","yellow"];

ce(2,1,"black","white");

alert(aColors);//outputs ["red","green","black","white", "yellow"]