Nodejs Number Calculate repr()

Method Source Code

Number.prototype.repr = function () {
    var digits = (arguments.length > 0)? arguments[0] : undefined;
    if (typeof digits !== "number") {
        return Number(this);
    }//from ww w.  j a  va2s  .  c om
    if (digits <= 0) {
        return Math.round(this);
    }
    var factor = Math.pow(10, digits);
    return Math.round(this * factor) / factor;
};

Related

1. popCount()

   Number.prototype.popCount = function() {
     var v = this.valueOf();
     v = v - ((v >> 1) & 0x55555555);                
     v = (v & 0x33333333) + ((v >> 2) & 0x33333333); 
     return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
   };
   

2. powerOf(power)

   Number.prototype.powerOf = function(power) {
     return Math.pow(this, power);
   };
   

3. randStr()

   Number.prototype.randStr = function() {
       var alpha = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
       var res = '';
       for(var i = 0; i < this; i++) {
           res += alpha[Math.floor(Math.random() * alpha.length)];
       return res;
   

4. range(a, b, i)

   Number.prototype.range  = function (a, b, i) {
       i = i || true;
       var min = Math.min.apply(Math, [a, b]),
           max = Math.max.apply(Math, [a, b]);
       return i ? this >= min && this <= max : this > min && this < max;
   };
   

5. repeat(n)

   Number.prototype.repeat = function(n){
     return this.toString().repeat(n);
   

6. reprLocale()

   Number.prototype.reprLocale = function () {
       var result,
           digits = (arguments.length > 0)? arguments[0] : undefined,
           number = String(this.repr(digits)),
           int = number.split(".")[0],
           intparts = [],
           float = (number.indexOf(".") >= 0)? number.split(".")[1] : undefined;
       while (int.length > 0) {
           if (int.length <= 3) {
   ...
   

7. reverse()

   Number.prototype.reverse = function() {
     return parseInt(this.toString().split('').reverse().join(''), 10);
   

8. rnd2()

   Number.prototype.rnd2 = function () {
     return Math.round(this.valueOf() * 100) / 100;
   

9. rotate()

   Number.prototype.rotate = Number.prototype.rotate || function () {
     return Math.floor((this / 10) + ((this % 10) * Math.pow(10, exports.digitLength(this) - 1)));
   };