Nodejs Float Format toFixed(d)

Method Source Code

/*//from w  w  w  .  j  ava 2s . c  o m
 * To fix the number toFixed function issue
 */
Number.prototype.toFixed = function (d) {
    var s = this + "";
    if (!d) d = 0;
    if (s.indexOf(".") == -1) s += ".";
    s += new Array(d + 1).join("0");
    if (new RegExp("^(-|\\+)?(\\d+(\\.\\d{0," + (d + 1) + "})?)\\d*$").test(s)) {
        var s = "0" + RegExp.$2, pm = RegExp.$1, a = RegExp.$3.length, b = true;
        if (a == d + 2) {
            a = s.match(/\d/g);
            if (parseInt(a[a.length - 1]) > 4) {
                for (var i = a.length - 2; i >= 0; i--) {
                    a[i] = parseInt(a[i]) + 1;
                    if (a[i] == 10) {
                        a[i] = 0;
                        b = i != 1;
                    } else break;
                }
            }
            s = a.join("").replace(new RegExp("(\\d+)(\\d{" + d + "})\\d$"), "$1.$2");

        } if (b) s = s.substr(1);
        return (pm + s).replace(/\.$/, "");
    } return this + "";

};

Related

1. formatFloat(num, pos)

   function formatFloat(num, pos) {
     var size = Math.pow(10, pos);
     return Math.round(num * size) / size;
   

2. toFix(digits)

   Number.prototype.toFix=function(digits){
       var f=parseInt(digits),
           n=Number(this),
           s=n.toString();
       var p=s.split(".");
       if(p[1]&&p[1].length>f){
           p[1]=p[1].substring(0,f);
           n=Number(p.join("."));
       }else{
   ...
   

3. toFixed(exponent)

   Number.prototype.toFixed = function(exponent) {
       if (exponent) {
           var result = (parseInt(this * Math.pow(10, exponent) + 0.5) / Math.pow(10, exponent)).toString();
           var count = 0;
           if (result.indexOf(".") > 0) {
               count = exponent - result.split(".")[1].length;
           } else {
               count = exponent;
               result += ".";
   ...
   

4. toFixed10(precision)

   Number.prototype.toFixed10 = function(precision) {
       return Math.round10(this, -precision).toFixed(precision);
   

5. toFixedBtoFixed ( precision )

   Number.prototype.toFixedB = function toFixed ( precision ) {
       var multiplier = Math.pow( 10, precision + 1 ),
           wholeNumber = Math.floor( this * multiplier );
       return (Math.round( wholeNumber / 10 ) * 10 / multiplier).toFixed(precision);
   

6. toFixedDown(digits)

   Number.prototype.toFixedDown = function(digits) {
       var n = this - Math.pow(10, -digits)/2;
       n += n / Math.pow(2, 53); 
       return n.toFixed(digits);