Nodejs Factorial Number Get factorial()

Method Source Code

Number.prototype.factorial = function() { 
    var n = 1;//from w w w.ja v a 2 s. com
    for(var i = 2; i <= this; i++)
        n*=i; 
    return n;
}
Number.prototype.permutation = function(r) { 
    return (this.factorial() / (this-r).factorial())
}


function permutate(p) {
    var states = new Number(p.length)
    console.log( states.permutation(states) )
}

function proofRow(n, pvar, rule ) {
   var s = n + "\t" + pvar + "\t" + rule
   console.log(s)
}

module.exports = {
  chat: function chat() {
      var argsv = chat.arguments
      var s=""
      for(var ea in argsv) {
         if(argsv[ea] != undefined)
            s += argsv[ea] + " " 
      }
      console.log(s)
  },
  solidify: function solidify(ary) {
   for(var i in ary) {
      if(ary[i] == undefined || ary[i] == '')
         ary.splice(i,1)
   }
   return ary
   }
};

Related

1. factorial()

   Number.prototype.factorial = function() { 
     if (this <= 1) return 1;
     var n = this;
     var sum = n;
     while(n > 1) sum *= --n;
     return sum;
   };