Nodejs Array Subset isSubsetOf(arr)

Method Source Code

/*//  ww w .  j  a v  a 2s  .  com
 * Make an array method that can return whether or not a context array is a
 * subset of an input array.  To simplify the problem, you can assume that neither
 * array will contain objects or arrays as elements within them.
 * Extra credit: Make the method work for arrays that contain objects and/or arrays as elements.
*/


Array.prototype.isSubsetOf = function (arr) {
  var objectify = function(arr) {
    var obj = {};
    for (var i = 0; i < arr.length; i++) {
      obj[arr[i]] = true;
    }
    return obj;
  };
  var obj = objectify(arr);
  for (var j = 0; j < this.length; j++) {
    if (obj[this[j]] === undefined) {
      return false;
    }
  }
  return true;
};

var test = [['a', 'b'], {'a': 1, 'b': 2}, 'a', 'c'];
console.log(test.isSubsetOf(['c', ['a', 'b'], {'a': 1, 'b': 2}, 'a', 'b']));

Related

1. isSubsetOf()

   Array.prototype.isSubsetOf = function() {
       var args=arguments[0];
       var len=this.length;
       var i;
       var counter=0;
       console.log(args);
       for(i=0; i<len; i++){
           if(args.indexOf(this[i])>=0){
               counter++;
   ...
   

2. isSubsetOf(arr)

   Array.prototype.isSubsetOf = function(arr) {
     return isSubsetObjs(this, objectify(arr));
   };
   var isSubsetObjs = function(arr, obj2) {
     for (var i = 0; i < arr.length; i++) {
       if (!obj2.hasOwnProperty(arr[i])) { 
        return false; 
     } return true;
   ...
   

3. isSubsetOf(arr)

   Array.prototype.isSubsetOf = function (arr) {
     for (var i = 0; i < this.length; i++) {
       if (arr.indexOf(this[i]) === -1) {
         return false; 
     return true; 
   }; 
   

4. isSubsetOf(arr)

   Array.prototype.isSubsetOf = function (arr) {
     let result = 0;
     for (let i = 0; i < this.length; i += 1) {
       for (let p = 0; p < arr.length; p += 1) {
         if (this[i] === arr[p]) {
           result += 1;
           break;
       if (i + 1 !== result) {
         return false;
     return true;
   };
   const b = ['merge','reset','reset']
   console.log(b.isSubsetOf(['reset','merge','add','commit']));
   const a = ['commit','push','blame'];
   console.log(a.isSubsetOf(['commit','rebase','push','blame']));
   

5. isSubsetOf(arr)

   Array.prototype.isSubsetOf = function (arr) {
     var subArr = this;
     var words = {};
     for (var i = 0; i < arr.length; i++) {
       if (!words[arr[i]]) {
         words[arr[i]] = true;
     for (var i = 0; i < subArr.length; i++) {
   ...
   

6. isSubsetOf(arr)

   Array.prototype.isSubsetOf = function (arr) {
     var objectify = function (arr) {
       var obj = {};
       for (var i = 0; i < arr.length; i++) {
         obj[arr[i]] = true;
       return obj;
     };
     var obj = objectify(arr);
   ...
   

7. isSubsetOf(array)

   Array.prototype.isSubsetOf = function(array) {
     return this.reduce(function (acc, val) {
       if (acc) {
         return array.includes(val);
       return false;
     }, true)
   };