Nodejs Array Contain contains(obj)

Method Source Code

'use strict';// w w  w.  j  a va2s. c  om
const list = require('./list.json');
const items = [];
const duplicates = [];

Array.prototype.contains = function(obj) {
  let i = this.length;
  while (i--) {
    if (this[i] == obj) {
        return true;
    }
  }
  return false;
}

for (let i = 0; i < list.length; i++){
  const title = list[i].title;
  if(!items.contains(title)){
    items.push(title);
  }else{
    duplicates.push(title);
  }
}
console.log(duplicates)

Related

1. contains(obj)

   'use strict';
   Array.prototype.contains = function(obj) {
       var i = this.length;
       while (i--) {
           if (this[i] == obj) {
               return true;
       return false;
   ...
   

2. contains(obj)

   Array.prototype.contains = function(obj) {
     var i = this.length;
     while (i--) {
       if (this[i] === obj) {
         return true;
     return false;
   

3. contains(obj)

   Array.prototype.contains = function (obj) {
       return this.indexOf(obj) > -1;
   };
   

4. contains(obj)

   Array.prototype.contains = function(obj) {
       var i = this.length;
       while (i--) {
           if (this[i] === obj) {
               return true;
       return false;
   };
   ...
   

5. contains(obj)

   Array.prototype.contains = function(obj) {
     var index = this.length;
     while (index--) {
       if (this[index] == obj) {
         return true;
     return false;
   };
   ...
   

6. contains(obj)

   Array.prototype.contains = function(obj) {
     let i = this.length;
     while (i--) {
       if (this[i] == obj) {
           return true;
     return false;
   

7. contains(obj)

   Array.prototype.contains = function(obj){
     return this.indexOf(obj)>-1;
   };
   

8. contains(obj)

   Array.prototype.contains = function(obj) {
       var i = this.length;
       while (i--) {
           if (this[i] === obj) {
               return true;
       return false;
   };
   ...
   

9. contains(obj)

   Array.prototype.contains = function (obj) {
       return this.indexOf(obj) >= 0;
   };