map_practice

1. Start with an array of numbers and create a new array with each number times 3.
  For example, [1, 2, 3] becomes [3, 6, 9].

2. Start with an array of strings and create a new array with each string upcased.
  For example, ["hello", "goodbye"] becomes ["HELLO", "GOODBYE"].

3. Start with an array of hashes and create a new array of string values from each hash's :name key.
  For example, [{name: "Alice", age: 27}, {name: "Blane", age: 16}] becomes ["Alice", "Blane"].

4. Start with an array of numbers and create a new array with each number plus 7.
  For example, [1, 2, 3] becomes [8, 9, 10].

5. Start with an array of strings and create a new array with each string's length.
  For example, ["hello", "goodbye"] becomes [5, 7].

6. Start with an array of hashes and create a new array of number values from each hash's :age key.
  For example, [{name: "Alice", age: 27}, {name: "Blane", age: 16}] becomes [27, 16].

7. Start with an array of numbers and create a new array with each number divided by 2.
  For example, [1, 2, 3] becomes [0.5, 1.0, 1.5].

8. Start with an array of strings and create a new array with each string's first letter only.
  For example, ["hello", "goodbye"] becomes ["h", "g"].

9.  Start with an array of hashes and create a new array of number values from each hash's :age key times 2.
  For example, [{name: "Alice", age: 27}, {name: "Blane", age: 16}] becomes [54, 32].

10. Start with an array of numbers and create a new array with each number converted into a string.
  For example, [1, 2, 3] becomes ["1", "2", "3"].
  
SOLUTIONS: https://github.com/TaylorOD/Deliberate_Practice-JavaScript/blob/master/solution_key/map_practice_solutions.js