《JavaScript高级程序设计》读书笔记之九：本地对象Array
《JavaScript高级程序设计》读书笔记之九：本地对象Array创建Array对象//onevar aValues=new Array();//twovar aValues=new Array(20);//threevar aColors=new Array();aColors="red";aColors="green";aColors="blue";//fourvar aColors=new Array("red","green","blue");//fivevar aColors=["red","green","blue"];
复制代码join && split
join:连接字符串var aColors=["red","green","blue"];alert(aColors.join(","));//outputs "red,green,blue"alert(aColors.join("-spring-"));//outputs "red-spring-green-spring-blue"alert(aColors.join("]["));//outputs "red][blue"
复制代码split:分拆字符串var sColors="red,green,blue";var aColors=sColors.split(",");//outputs ["red", "green", "blue"]var redColors=aColors.split("");//outputs ["r", "e", "d"]
复制代码concat && slice
concat:追加数组var aColors=["red","green","blue"];var aColors2=aColors.concat("yellow","purple");alert(aColors);//outputs ["red", "green", "blue"]alert(aColors2);//outputs ["red", "green", "blue", "yellow", "purple"]
复制代码slice:返回具有特定项的新数组var aColors=["red","green","blue","yellow","purple"];var aColors2=aColors.slice(1);//outputs ["green","blue","yellow","purple"]var aColors3=aColors.slice(1,4);//outputs ["green","blue","yellow"]
复制代码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var stack=new Array;stack.push("red");stack.push("green");stack.push("blue");alert(stack);//outputs ["red","green","blue"]var vItem=stack.pop();alert(vItem);//outputs ["blue"]alert(stack);//otputs ["red","green"]
复制代码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var aColors=["red","green","blue"];var vItem=aColors.shift();alert(aColors);//outputs ["green","blue"]alert(vItem);//outputs ["red"]aColors.unshift("black");alert(aColors);//outputs ["black","green","blue"]
复制代码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)var aColors=["blue","green","red"];aColors.reverse();alert(aColors);//outputs ["red","green","blue"]aColors.sort();alert(aColors);//outputs ["blue","green","red"]
复制代码注意：var aColors=;aColors.sort();alert(aColors);//outputs
复制代码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var aColors=["red","green","blue","yellow"];aColors.splice(0,2);alert(aColors);//outputs ["blue", "yellow"]
复制代码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var aColors=["red","green","blue","yellow"];aColors.splice(2,0,"black","white");alert(aColors);//outputs ["red","green","black","white","blue", "yellow"]
复制代码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
var aColors=["red","green","blue","yellow"];aColors.splice(2,1,"black","white");alert(aColors);//outputs ["red","green","black","white", "yellow"]
复制代码 谢谢分享
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