Javascript Lists Homework

After going through the Javascript lists lesson work on these hacks in your own repository

Hack 1 – Add Up Numbers

Make a list of numbers. Write code to:

Find the total sum.
Find the average.

%%javascript
let numbers = [4, 7, 1, 9, 6, 7, 10];

let total = 0;
for (let num of numbers) {
    total += num;
}

console.log(`Total points: ${total}`);  // 44

let average = total / numbers.length;
console.log(`Average score: ${average}`);  // 6.285714285714286

<IPython.core.display.Javascript object>

Hack 2 – Count Repeats

Make a list with repeated items. Write code to count how many times each item appears.

%%javascript
let items = ["cat", "dog", "cat", "bird", "bird", "bird"];

// Create empty object to store counts
let frequency = {};

// Count each item
for (let item of items) {
    if (frequency[items]) {
        frequency[items]++;
    } else {
        frequency[items] = 1;
    }
}

console.log(frequency);
// Output: {cat: 2, dog: 1, bird: 3}

<IPython.core.display.Javascript object>

Hack 3 – Keep Only Evens

Make a list of numbers. Write code to create a new list with only even numbers.

%%javascript
// Hack 3 – Keep Only Evens
let numbers = [3, 8, 5, 12, 7, 9, 13, 31, 66, 18];

// Create empty array for even numbers
let evenNumbers = [];

// Loop through numbers and keep only evens
for (let num of numbers) {
    if (num % 2 === 0) {
        evenNumbers.push(num);
    }
}

console.log(evenNumbers);  // [8, 12, 66, 18]

<IPython.core.display.Javascript object>