Javascript Lists Homework

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

Hack 1 – Add Up Numbers

Make a list of numbers. Write code to:

  1. Find the total sum.
  2. Find the average.
%%js 
// Hack 1 – Add Up Numbers
let numbers = [4, 7, 1, 9, 6, 7, 10];
let sum = 0;
for (let i = 0; i < numbers.length; i++) {
    sum += numbers[i];
}

let average = sum / numbers.length;

console.log("Sum:", sum);
console.log("Average:", average);



<IPython.core.display.Javascript object>

Console Output

Hack 2 – Count Repeats

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

%%js 
// Hack 2 – Count Repeats
let items = ["cat", "dog", "cat", "bird", "bird", "bird"];

// Write your code here:
let counts = {};

for (let i = 0; i < items.length; i++) {
    let item = items[i];
    if (counts[item]) {
        counts[item]++;
    } else {
        counts[item] = 1;
    }
}

console.log(counts);

<IPython.core.display.Javascript object>

Console Output

Hack 3 – Keep Only Evens

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

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

// Write your code here:

let evens = numbers.filter(num => num % 2 === 0);
console.log(evens);

<IPython.core.display.Javascript object>

Console Output