JavaScript实现文本倒转

[f32414]

<!DOCTYPE html>        
<html lang="en">        
<head>        
	<meta charset="UTF-8">        
	<title>Document</title>        
</head>        
<body>        
	        
</body>        
</html>        
<script>        
	var str = ('123456789');        
	var nstr = "";        
	var a;        
	for (var i = 0; i < str.length+1; i++) {        
		console.log(a = str.substring(str.length-i,str.length-i+1));        
			nstr +=a;        
	};        
	document.write(nstr);        
</script>  

[f32414]

第一次发东西，不太熟悉。。。求管理员大大拯救

[Eureka]

@f32414: 具体看这里 https://www.shiqidu.com/p/164

[Eureka]