Listing Object Keys and Values

If you know what keys an object has, it's easy to get the corresponding values. But you don't always know what keys an object has. Here's how you'd get a list:

const scrabblePoints = { t: 1, j: 8, k: 5, q: 10 };
Object.keys(scrabblePoints);
// ['t', 'j', 'k', 'q']

You could use that list of keys to get a list of all the values. But JavaScript has a more convenient method:

Object.values(scrabblePoints);
// [1, 8, 5, 10]

You can even get a list of key-value pairs:

Object.entries(scrabblePoints);
// [['t', 1], ['j', 8], ['k', 5], ['q', 10]]

Tests

1. Write a function -- countKeys -- that takes an object as its only input and return the number of keys it contains. For example, if you passed to countKeys the scrabblePoints object defined above, it should return 4.
2. Write another function -- countCharacters -- that takes an object as its only input and returns the total number of characters in all its string values. Hint: test if a value is a string like so: if (typeof value === 'string').