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Create a Map Data Structure

The next few challenges will cover maps and hash tables. Maps are data structures that store key-value pairs. In JavaScript, these are available to us as objects. Maps provide rapid lookup of stored items based on key values and are very common and useful data structures.

Let's get some practice creating our own map. Because JavaScript objects provide a much more efficient map structure than anything we could write here, this is intended primarily as a learning exercise. However, JavaScript objects only provide us with certain operations. What if we wanted to define custom operations? Use the Map object provided here as a wrapper around a JavaScript object. Create the following methods and operations on the Map object:

  • add accepts a key, value pair to add to the map.
  • remove accepts a key and removes the associated key, value pair
  • get accepts a key and returns the stored value
  • has accepts a key and returns true if the key exists or false if it doesn't.
  • values returns an array of all the values in the map
  • size returns the number of items in the map
  • clear empties the map

Tests

  • Waiting: 1. The Map data structure should exist.
  • Waiting: 2. The Map object should have the following methods: add, remove, get, has, values, clear, and size.
  • Waiting: 3. The add method should add items to the map.
  • Waiting: 4. The has method should return true for added items and false for absent items.
  • Waiting: 5. The get method should accept keys as input and should return the associated values.
  • Waiting: 6. The values method should return all the values stored in the map as strings in an array.
  • Waiting: 7. The clear method should empty the map and the size method should return the number of items present in the map.
/**
* Your test output will go here
*/