Nodejs Float Format toFixed(exponent)

Method Source Code

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 {/* w  ww  . j ava 2  s  .c  o m*/
            count = exponent;
            result += ".";
        }

        for (count; count > 0; count--) {
            result += "0";
        }

        return result;
    } else {
        return parseInt(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(d)

   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);
   ...
   

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);
   

7. toFixedDown(digits)

   Number.prototype.toFixedDown = function(digits) {
     var re = new RegExp('(\\d+\\.\\d{' + digits + '})(\\d)'),
         m = this.toString().match(re);
     return m ? parseFloat(m[1]) : this.valueOf();
   };