Javascript Array isSubsetOf(inputArray)

'use strict';/*from www  . j a va2 s  .  c  o  m*/
Array.prototype.isSubsetOf = function(inputArray) {
  var exist = true;
  for(var i = 0; i < this.length; i++) {
    if(inputArray.indexOf(this[i]) === -1) {
      exist = false;
    }
  }
  return exist;
};

Array.prototype.isSubsetOf = function(inputArray) {
  var exists = true;

  for (var i = 0; i < this.length; i++) {
    if (inputArray.indexOf(this[i]) === -1) {
      exists = false;/*w  w  w.j  a v a2s  . c  om*/
    }
  }

  return exists;
};

// Is Subset Of/*w  w  w.j av  a  2  s. c  o m*/
// 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 both arrays will contain only strings.

Array.prototype.isSubsetOf = function(inputArray) {
  for(var i = 0; i < this.length; i++){
    if(!inputArray.includes(this[i])){
      return false;
    }
  }
  return true;
};

//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 both arrays will 
//contain only strings.

Array.prototype.isSubsetOf = function(inputArray) {
  //var isSubset = true;
  for (var i = 0; i < this.length; i++) {
    var contains = false;
    for (var j = 0; j < inputArray.length; j++) {
      if (inputArray[j] === this[i]) {
        contains = true;//from ww w  .  ja v a 2 s. co m
      }
    }
    if (!contains) {
      return false;
    }
  }
  return true;
};