Nodejs Array Sort sortDescending()

Method Source Code

function getLargestPalindrome() {
  products = fillMultiples().sortDescending();
  for (i = 0; i < products.length; i++) {
    if (products[i].toString().isPalindrome()) {
      return products[i];
    }//from  www . j a v  a  2s  .c o m
  }
}

function fillMultiples() {
  var products = []
  for (i = 100; i < 1000; i++ ) {
    for (j = 100; j < 1000; j++ ) {
      products.push(i*j)
    }
  }
  return products
}

Array.prototype.sortDescending = function() {
  return this.sort(function(a,b) { return b - a })
}

String.prototype.isPalindrome = function() {
  return this == this.reverse() ? true : false
}

String.prototype.reverse = function() {
    return this.split('').reverse().join('');
}

console.log(getLargestPalindrome());

Related

1. sortByFrequency()

   Array.prototype.sortByFrequency = function () {
     var freq = {};
     this.map(function(e, i, a){
       if(e in freq){
         freq[e]++;
       } else {
         freq[e] = 1;
     });
   ...
   

2. sortByID()

   var library = [ 
          title:  'The Road Ahead',
          author: 'Bill Gates',
          libraryID: 1254
      },
          title: 'Walter Isaacson',
          author: 'Steve Jobs',
   ...
   

3. sortByID(argument)

   'use strict';
   Array.prototype.sortByID = function(argument){
     this.sort(function(x,y){
       return x.libraryID > y.libraryID;
     });
   };
   var library = [ 
          title:  'The Road Ahead',
   ...
   

4. sortByKeysortByKey(key, dsc)

   Array.prototype.sortByKey = function sortByKey(key, dsc) {
     return this.sort(function(a, b) {
         var x = a[key]; 
         var y = b[key];
         if (dsc ==='dsc') {
           return (x === undefined && y === undefined ? 0 : (x < y) || x === undefined ? 1 : ((x > y) || y === undefined ? -1 : 0));
         return (x === undefined && y === undefined ? 0 : (x < y) || x === undefined ? -1 : ((x > y) || y === undefined ? 1 : 0)); 
     });
   ...
   

5. sortByNumber()

   Array.prototype.sortByNumber = function() {
    return this.sort(function(a, b) { return a - b; }); 
   

6. sortNumber(a)

   Array.prototype.sortNumber = function(a) {
     if (a == true) {
       return this.sort(function(d, c) {
         return d - c
       }).reverse()
     } else {
       return this.sort(function(d, c) {
         return d - c
       })
   ...
   

7. sortObject(field)

   Array.prototype.sortObject = function(field) {
     if (typeof this[0][field] === 'undefined') return this;
     var len = this.length,
       i,
       j,
       flag,
       next,
       temp;
     for (i = 1; i < len; i++) {
   ...
   

8. sort_text(direction, index)

   Array.prototype.sort_text = function(direction, index) {
       direction = direction === undefined ? 'asc' : direction;
       direction = direction === 'asc' ? 1 : -1;
       this.sort(function(a, b) {
           if (a[index] < b[index]) return -direction;
           if (a[index] > b[index]) return direction;
           return 0;
       })
   };
   ...
   

9. sort()

   Array.prototype.sort = function(){
     var a = this;
     for(var i = 0;i<a.length-1;i++){
       var t = i;
       for(var j = i+1;j<a.length;j++)
         if(a[t]>a[j])
           t = j;
       if(t!=i)
         this.swap(i,t);
   ...