Nodejs Number Calculate fe(x)

Method Source Code

//-----------------------------------------------
// Floating point comparison
//< returns true if approximately equal, false if not
Number.prototype.fe = function(x)
{
   var s = x.toString();
   var point = s.search(/\./);
   /*from   w ww  .  j a va2 s  .  c  o  m*/
   // if not a floating point number
   if (point == -1)
   {
      return (Math.abs(this - x) < 0.5);      // if x = 123 then [122.5 through 123.5] are true
   }
   else
   {
      var significantDigits = s.length - point;
      var epsilon = Number("5E-" + significantDigits);
      return (Math.abs(this - x) < epsilon);      // if x = 0.12567 then [0.125665 through 0.125675)] are true
   }
};

Related

1. div10()

   Number.prototype.div10 = function () {
     return this/10;
   Object.prototype.say = function (s) {
    console.log('I say ' + s);
   var o = {};
   o.say("Hello");
   var n = 120;
   ...
   

2. double()

   Number.prototype.double = function() {
     return this * 2;
   };
   

3. doubleDigitalize()

   "use strict";
   Number.prototype.doubleDigitalize = function() {
     const numberString = this.toString();
     return numberString.length < 2 ? "0" + numberString : numberString;
   };
   

4. equals(another)

   Number.prototype.equals = function (another) {
       return this - another === 0;
   };
   

5. exp()

   Number.prototype.exp = function() {
     return Math.exp(this);
   };
   

6. fillZero(len)

   Number.prototype.fillZero = function (len)
     var s = this.toString(10);
     while (s.length<len) s = "0" + s;
     return s;
   

7. firstDigit()

   Number.prototype.firstDigit = Number.prototype.firstDigit || function () {
     let number = this;
     while (number >= 10) {
       number = Math.floor(number / 10);
     return number;
   };
   

8. fix(n)

   Number.prototype.fix = function (n) {
       var val = String(this);
       n = Math.abs(n);
       val = val.split('.');
       val[1] = val[1] || '';
       var m = val[1].length;
       if (m < n) {
           m = n - m;
           while (m > 0) {
   ...
   

9. fizz()

   Number.prototype.fizz = function() {
       return this % 3 === 0 ? "fizz" : "";
   };
   Number.prototype.buzz = function() {
       return this % 5 === 0 ? "buzz" : "";
   };
   for (var i = 1; i <= 15; i++) {
       var candidate = Number(i).fizz() + Number(i).buzz();
       console.log(candidate ? candidate : i);
   ...