js实现26进制和10进制之间的转换

        //将26进制转10进制
        var ConvertNum = function (str) {
            var n = 0;
            var s = str.match(/./g);//求出字符数组
            var j = 0;
            for (var i = str.length - 1, j = 1; i >= 0; i--, j *= 26) {
                var c = s[i].toUpperCase();
                if (c < 'A' || c > 'Z') {
                    return 0;
                }
                n += (c.charCodeAt(0) - 64) * j;
            }
            return n;
        }
        //测试
        var teststr = "AB";
        alert(ConvertNum(teststr));
        //将10进制转26进制
        var Convert26=function(num){
            var str="";
            while (num > 0){
                var m = num % 26;
                if (m == 0){
                    m = 26;
                }
                str = String.fromCharCode(m + 64) + str;
                num = (num - m) / 26;
            }
            return str;
        }

        //测试
        var num = 28;
        alert(Convert26(num));