Three ways to implement string inversion in javascript

1. Method 1

var str = "abcdef"; 
console.log( str.split("").reverse().join("") )；

2. Method 2

var str="abcdef" 
var i=str.length; 
i=i-1; 
for (var x = i; x >=0; x--) 
{ 
	document.write(str.charAt(x)); 
}

3. Method three

function reverse(str) 
{ 
    if(str.length == 0)return null; 
    var i = str.length; 
    var dstr = ""; 
    while(--i >= 0) 
    { 
        dstr += str.charAt(i);  
    } 
    return dstr; 
} 
var str = "abcdef"; 
str = reverse(str); 
document.write(str); 

Reference address: http://www.jb51.net/article/43648.htm