js中的数组

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java中的数组：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>无标题文档</title></head><script>//创建数组的三种方式var arr1=[1,3,2];var arr2=new Array(3);var arr3=new Array(1,2,3); document.write(arr1.length); document.write("<hr>");//字符串的连接操作document.write(arr1.concat(arr3));document.write("<hr>");//分割字符arr2[0]="a";arr2[1]="b";arr2[2]="c";document.write(arr2);//默认是逗号document.write("<br>");document.write(arr2.join("**"));document.write("<hr>");document.write(arr2);document.write("arr2 old length:"+arr2.length);document.write("<hr>");document.write(arr2.push("d"));//返回值是新数组的长度document.write("<hr>");document.write(arr2);document.write("arr2 new length:"+arr2.length);document.write("<hr>");var arr4=["aaa","bbb","ccc","sss"];document.write(arr4);document.write("<hr>");document.write("return:"+arr4.pop());document.write("<hr>");document.write(arr4);document.write("<hr>");//数组元素颠倒顺序document.write(arr1.reverse());</script><body></body></html>

页面显示：

1,3,2,1,2,3

a,b,c
a**b**c

a,b,carr2 old length:3

a,b,c,darr2 new length:4

aaa,bbb,ccc,sss

return:sss

aaa,bbb,ccc

2,3,1

以下内容为转载：

2、js的Array对象
** 创建数组（三种）
- var arr1 = [1,2,3];
- var arr2 = new Array(3); //长度是3
- var arr3 = new Array(1,2,3); //数组中的元素是1 2 3

- var arr = []; //创建一个空数组

** 属性：length：查看数组的长度

** 方法
- concat方法：数组的连接
* var arr11 = [1,2,3];
var arr12 = [4,5,6];
document.write(arr11.concat(arr12));

- join()：根据指定的字符分割数组
* var arr13 = new Array(3);
arr13[0] = "a";
arr13[1] = "b";
arr13[2] = "c";

document.write(arr13);
document.write(" ");
document.write(arr13.join("-"));

- push():向数组末尾添加元素，返回数组的新的长度
** 如果添加的是一个数组，这个时候把数组当做一个整体字符串添加进去

* //push方法
var arr14 = new Array(3);
arr14[0] = "tom";
arr14[1] = "lucy";
arr14[2] = "jack";
document.write("old array: "+arr14);

document.write(" ");
document.write("old length:"+arr14.length);

document.write(" ");
document.write("new length: "+arr14.push("zhangsan"));

document.write(" ");
document.write("new array: "+arr14);

* var arr15 = ["aaa","bbb","ccc"];
var arr16 = ["www","qqq"];

document.write("old array:"+arr15);
document.write(" ");
document.write("old length:"+arr15.length);

document.write(" ");
document.write("new length:"+arr15.push(arr16));
document.write(" ");
document.write("new array: "+arr15);
for(var i=0;i<arr15.length;i++) {
alert(arr15[i]);
}

- pop()：表示删除最后一个元素，返回删除的那个元素
* var arr17 = ["zhangsan","lisi","wangwu","zhaoliu"];
document.write("old array: "+arr17);
document.write(" ");

document.write("return: "+arr17.pop());
document.write(" ");
document.write("new array: "+arr17);

- reverse():颠倒数组中的元素的顺序
* var arr17 = ["zhangsan","lisi","wangwu","zhaoliu"];
document.write("old array: "+arr17);
document.write(" ");

document.write("return: "+arr17.pop());
document.write(" ");
document.write("new array: "+arr17);

//reverse方法
document.write("<hr/>");
var arr18 = ["zhangsan1","lisi1","zhaoliu1","niuqi1"];
document.write("old array: "+arr18);
document.write(" ");
document.write("new array:"+arr18.reverse());

JS中的数组.

// 定义数组.

var arr1 = []; // 定义一个空数组

var arr2 = [11,22,33,44]; // 定义了一个有元素的数组.

var arr3 = [11,true,'abc']; // 定义一个数组存入不同的数据类型. 但是一般不建议这样使用.

for(var i = 0;i<arr3.length;i++){

alert(arr3[i]);

}

// 定义数组使用对象定义

var arr4 = new Array(); // 定义了一个空数组.

var arr5 = new Array(5); // 定义了一个长度为5的数组.

//alert(arr5[0]);

// alert(arr4.length);

var arr6 = new Array(1,2,3,4,5,6); // 定义了一个数组元素 1,2,3,4,5

arr6[100] = 10;

// 数组的长度是以数组的最大下标值 + 1

alert(arr6.length);

// 面试题

一下的语句那个是错误的( C )

A.var a = //;

B.var a = [];

C.var a = ();

D.var a = {};

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