Nodejs Array Check isNFromLastIndex(index, n)

Method Source Code

/**//www  .  j  a va2 s .  com
 * Determines if the given index is n elements from end of the array.
 * @param {number} index - The index to test from the end 
 * @param {number} n - the number of positions from the end.
 * @return {boolean} - True if index is n positions from the end of the array.
 */
Array.prototype.isNFromLastIndex = function(index, n) {
   return (this.length - 1 - n) == index;
}

Related

1. isDefined(key)

   Array.prototype.isDefined = function (key) {
       return this.filter(c => {
           if (key) return c[key];
           return !!c;
       });
   

2. isDistinct()

   Array.prototype.isDistinct = function() {
     this.sort();
     for (var i = 1; i < this.length; i++) {
       if (this[i - 1] == this[i])
         return false;
     return true;
   };
   

3. isInt()

   Array.prototype.isInt = function (){
     return this.filter(function(n){ return (typeof(n) === 'number') && (n%1 === 0)})
   };
   Array.prototype.even = function (){
     return this.isInt().filter(function(n){ return n%2 === 0})
   };
   Array.prototype.odd = function (){
     return this.isInt().filter(function(n){ return n%2 !== 0})
   };
   ...
   

4. isLastIndex(index)

   Array.prototype.isLastIndex = function(index) {
     return index == (this.length - 1);
   

5. isMember(b)

   Array.prototype.isMember = function (b) {
     return this.some(function (i) {
       return this == i
     }, b);
   

6. isNothing()

   Array.prototype.isNothing = function() {
     return this.length === 0;
   };
   

7. isNumberArray()

   'use strict';
   Array.prototype.isNumberArray = function() {
       return !this.some(x => typeof x != 'number');
   module.exports = function segmentNumbers(arr) {
       arr = arr.sort();
       if (!arr.isNumberArray()) return [];
       let container = [],
           items = [],
   ...
   

8. isSparse()

   Array.prototype.isSparse = function() {
     return this.length !== Object.keys(this).length;