Implement store class (hashSet) in JavaScript

Implement a simple store class (hashSet) in JavaScript with set(key, value), get(key), & has(key) methods.

Example

const store = new Store();

store.set('a', 10);
store.set('b', 20);
store.set('c', 30);

store.get('b'); // 20
store.has('c'); // true

Reading the problem statement we can derive that we have to create a simple function that will store the list of key-value pairs and will expose two methods, one to check if the key exists in the store and the second to get the value associated with the key, apart from these one more method to store the key-values.

We can do this by simply creating a function with an object that will store the key-value and these methods.

const Store = function(){
  //store the data
  this.list = {};
  
  //set the key-value in list
  this.set = function(key, value){
    this.list[key] = value;
  }
  
  //get the value of the given key
  this.get = function(key){
    return this.list[key];
  }
  
  //check if key exists
  this.has = function(key){
    return !!this.list[key];
  }
}

Input:
const store = new Store();
store.set('a', 10);
store.set('b', 20);
store.set('c', 30);
console.log(store.get('b'));
console.log(store.has('c'));
console.log(store.get('d'));
console.log(store.has('e'));

Output:
20
true
undefined
false