Assignment

The warmup exercises will be a bit abstract. But the in the hyfBay exercise the task will be a lot closer to a real world task.

1. Doubling of number

Say you would like to write a program that doubles the odd numbers in an array and throws away the even number.

Your solution could be something like this:

let numbers = [1, 2, 3, 4];
let newNumbers = [];

for (let i = 0; i < numbers.length; i++) {
  if (numbers[i] % 2 !== 0) {
    newNumbers[i] = numbers[i] * 2;
  }
}

console.log("The doubled numbers are", newNumbers); // [2, 6]

Rewrite the above program using map and filter don't forget to use arrow functions.

2. Codewars!

Complete these Katas:

• 8 kyu To square(root) or not to square(root)

• 8 kyu Removing Elements

3. Working with movies

cinema

Copy the movies array in the movies file. Use this array to do the following tasks:

1. Create an array of movies containing the movies with a short title (you define what short means)

2. Create an array of movie titles with long movie titles

3. Count the number of movies made between 1980-1989 (including both the years)

4. Create a new array that has an extra key called tag. The tag is based on the rating: Good (>= 7), Average (>= 4 and < 7), Bad (< 4)

5. Using chaining, first filter the movies array to only contain the movies rated higher than 6. Now map the movies array to only the rating of the movies.

6. Count the total number of movies containing any of following keywords: Surfer, Alien or Benjamin. So if there were 3 movies that contained Surfer, 1 with Alien and 2 with Benjamin, you would return 6. Can you make sure the search is case insensitive?

7. Create an array of movies where a word in the title is duplicated. e.g. "Star Wars: The Clone Wars" the word Wars is duplicated. Here are some made-up examples of movies with duplicated words in the title: "The three men and the pistol", "Chase three - The final chase"

8. Calculate the average rating of all the movies using .reduce() Optional

9. Count the total number of Good, Average and Bad movies using .reduce(). A return could be e.g. {goodMovies: 33, averageMovies: 45, goodMovies: 123} Optional