JS formatting numbers

Recently, I have been involved in the processing of a lot of monetary values ​​when developing a mall. I will soon have to convert the data (for example: 12345-->1,2345...)

//Format the number fmoney("12345.675910", 3) , return 12,345.676

fmoneyFormatPoint : function(s, n) {  
        n = n > 0 && n <= 20 ? n : 2;  
        s = parseFloat((s + "").replace(/[^\d\.-]/g, "")).toFixed(n) + "";  
        var l = s.split(".")[0].split("").reverse(), r = s.split(".")[1];  
        t = "";  
        for (i = 0; i < l.length; i++) {  
            t += l[i] + ((i + 1) % 3 == 0 && (i + 1) != l.length ? "," : "");  
        }  
var amt = t.split("").reverse().join("") + "." + r;
        return amt;  //返回带有逗号的值
//return amt.replace(new RegExp(/,/g),&#39;&#39;);//返回没有带逗号的值
    }