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  • JavaScript对象和数组

    <!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>数组与对象</title>
    <script type="text/javascript">
        //创建数组
        var arr = new Array();
    	arr[0] = 123;
    	arr[1] = "Hello";
    	arr[2] = 12.23;
    	arr[3] = true;
    	arr[6] = 45;
    	alert(arr[0]);//输出123
    	alert(arr.length);//输出4
    	alert(arr[4]);//输出undefined
    	alert(arr[arr.length-1]);//输出最后一个元素,true
    	
    	/*遍历数组*/
    	for(var i=0;i<arr.length && arr[i] != undefined;i++)
    	{
    		alert("数组第"+i+"元素:"+arr[i]);
    	}
    	
    	//创建数组并赋值
    	var b = new Array(1,2,3,4,5,6);
    	
    	//创建一个长度为0的数组
    	var d = [];
    	alert(d,length);//输出为0
    	
    	//创建数组
    	var date = new Array();
    	date[0] = 1234;
    	date[1] = "H";
    	date[2] = true;
    	date[3] = 120.12;
    	//向数组末尾添加元素
    	date.push(25);
    	alert(date[date.length-1]);//输出25
    	date.push(1,2,3,4);
    	alert(date.length);//输出9
    	
    	//delete删除元素,数组长度不变
    	delete date[0];
    	alert(date[0]);//输出undefined
    	alert(date.length);//输出9
    	
    	alert(date.join("#"));//输出#H#true#120.12#25#1#2#3#4
    	
    </script>
    </head>
    
    <body>
    </body>
    </html>
    

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  • 原文地址:https://www.cnblogs.com/hzcya1995/p/13315614.html
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