Nodejs Array Unique uniq()

Method Source Code

// dups//from   w  ww .j  ava 2s  . c om
Array.prototype.uniq = function () {
  var uniqueArray = [];

  for (var i = 0; i < this.length; i++) {
    if (uniqueArray.indexOf(this[i]) === -1) {
      uniqueArray.push(this[i]);
    }
  }

  return uniqueArray;
};

console.log([1, 1, 2, 2, 3, 3, 4, 4, 5, 5].uniq());

// twoSum
Array.prototype.twoSum = function () {
  var pairs = [];

  for (var i = 0; i < this.length; i++) {
    for (var j = (i + 1); j < this.length; j++) {
      if (this[i] + this[j] === 0) {
        pairs.push([i, j]);
      }
    }
  }

  return pairs
};

console.log([-1, 0, 2, -2, 1].twoSum());

// transpose
Array.prototype.transpose = function () {
  var columns = [];
  for (var i = 0; i < this[0].length; i++) {
    columns.push([]);
  }

  for (var i = 0; i < this.length; i++) {
    for (var j = 0; j < this[i].length; j++) {
      columns[j].push(this[i][j]);
    }
  }

  return columns;
};

console.log([[0, 1, 2], [3, 4, 5], [6, 7, 8]].transpose());

Related

1. uniq()

   Array.prototype.uniq = function () {
       var flag = false;
       var result = [];
       for(var i=0;i<this.length;i++) {
           if(result.indexOf(this[i]) == -1) {
               if(this[i]==this[i]) {
                   result.push(this[i]);
               else if(!flag) {
   ...
   

2. uniq()

   Array.prototype.uniq = function(){
     var uniqArray = [];
     for (var i = 0; i < this.length; i++){
       if (uniqArray.indexOf(this[i]) === -1)
         uniqArray.push(this[i])
     return uniqArray
   ...
   

3. uniq()

   Array.prototype.uniq = function() {  
       var temp = {};
       for(var i=0; i<this.length; i++)  {  
               temp[this[i]] = 1;
       this.length = 0;
       for(var e in temp) {  
           this.push(e);
       this.sort()
       return this;  
   function xmlencode(string) {
       return string.replace(/\&/g,'&'+'amp;').replace(/</g,'&'+'lt;')
           .replace(/>/g,'&'+'gt;').replace(/\'/g,'&'+'apos;').replace(/\"/g,'&'+'quot;');
   

4. uniq()

   Array.prototype.uniq = function () {
     var uniq_arr = [];
     for (var i = 0; i < this.length; i++) {
       var included = false;
       for (var j = 0; j < uniq_arr.length; j++) {
         if (uniq_arr[j] === this[i]) {
           included = true;
           break;
         };
   ...
   

5. uniq()

   Array.prototype.uniq = function() {
     let res = [];
     for(let i=0; i < this.length; i++) {
       let value = this[i];
       if (!res.includes(value)) res.push(value);
     return res;
   };
   console.log([1,2,2,1,1,3].uniq());
   ...
   

6. uniq()

   "use strict";
   Array.prototype.uniq = function () {
     let uniqueArray = [];
     for (let i = 0; i < this.length; i++) {
       if (uniqueArray.indexOf(this[i]) === -1) {
         uniqueArray.push(this[i]);
     return uniqueArray;
   ...
   

7. uniq()

   Array.prototype.uniq = function () {
     var newArray = [];
     for (var i = 0; i < this.length; i++) {
       var el = this[i];
       if (newArray.indexOf(el) === -1) {
         newArray.push(el);
     return newArray;
   ...
   

8. uniq()

   Array.prototype.uniq = function() {
     var dups = {},
         cleanArray = [];
         array = this,
         i = 0,
         len = array.length;
     if(this.constructor !== Array) {
       throw new TypeError ('Can only call this method on an array');
     for(i; i < len; i++) {
       if(!dups[array[i]]) {
         cleanArray.push(array[i]);
         dups[array[i]] = true;
     return cleanArray;
   

9. uniq()

   Array.prototype.uniq = function (){
     let result = [];
     for (let i = 0; i < this.length; i++) {
       if (result.includes(this[i])) {
         continue;
       } else {
         result.push(this[i]);
     return result;
   };
   console.log([1, 2, 1, 3, 3].uniq());
   console.log([1, 2, 3, 4].uniq());