```js
function Set() {
// the var collection will hold the set
var collection = [];
// this method will check for the presence of an element and return true or false
this.has = function(element) {
return (collection.indexOf(element) !== -1);
};
// this method will return all the values in the set
this.values = function() {
return collection;
};
// this method will add an element to the set
this.add = function(element) {
if(!this.has(element)){
collection.push(element);
return true;
}
return false;
};
// this method will remove an element from a set
this.remove = function(element) {
if(this.has(element)){
var index = collection.indexOf(element);
collection.splice(index,1);
return true;
}
return false;
};
// this method will return the size of the collection
this.size = function() {
return collection.length;
};
// this method will return the union of two sets
this.union = function(otherSet) {
var unionSet = new Set();
var firstSet = this.values();
var secondSet = otherSet.values();
firstSet.forEach(function(e){
unionSet.add(e);
});
secondSet.forEach(function(e){
unionSet.add(e);
});
return unionSet;
};
// this method will return the intersection of two sets as a new set
this.intersection = function(otherSet) {
var intersectionSet = new Set();
var firstSet = this.values();
firstSet.forEach(function(e){
if(otherSet.has(e)){
intersectionSet.add(e);
}
});
return intersectionSet;
};
// this method will return the difference of two sets as a new set
this.difference = function(otherSet) {
var differenceSet = new Set();
var firstSet = this.values();
firstSet.forEach(function(e){
if(!otherSet.has(e)){
differenceSet.add(e);
}
});
return differenceSet;
};
// change code below this line
// change code above this line
}
```
## Solution