Javascript Exercises: Functions and Arrays (basics)

Table of Contents

• Overview

• Functions exercises

  • About Functions exercises

  • List of Functions exercises

• Array exercises

  • About Array exercises

  • List of Array exercises

Overview

This repository showcases my progress and solutions for various JavaScript challenges during learning from The Odin Project, with a focus on fundamental concepts like functions, array manipulation and string operations.

These exercises were primarily assigned by The Odin Project.

This repo contains solutions to:

* **Function exercises** 

* **Array exercises**

Functions exercises

About Functions exercises

Developed as part of: Function basics: assignments from Foundations Course, The Odin Project Curriculum.

Creation Date: 22/06/2025

Completion Date: 22/06/2025

Status: Complete

List of Functions exercises

Exercise 1: add7

Write a function called add7 that takes one number and returns that number + 7.

Write function and test the output with console.log.

Exercise 2: multiply

Write a function called multiply that takes 2 numbers and returns their product.

Write function and test the output with console.log.

Exercise 3: capitalize

Write a function called capitalize that takes a string and returns that string with only the first letter capitalized.

Make sure that it can take strings that are lowercase, UPPERCASE or BoTh.

Exercise 4: lastLetter

Write a function called **lastLetter** that takes a string and returns the very last letter of that string: lastLetter("abcd") should return "d".  

Array Exercises

About Array exercises

Developed as part of: The Odin Project assignment, challenges sourced from javascript.info.

Creation Date: 16/07/2025

Completion Date: n/a

Status: In progress

List of Array exercises

Exercise 1: Camelize()

Write the function camelize(str) that changes dash-separated words like “my-short-string” into camel-cased “myShortString”.

That is: removes all dashes, each word after dash becomes uppercased.

Examples:

camelize("background-color") == 'backgroundColor';
camelize("list-style-image") == 'listStyleImage';
camelize("-webkit-transition") == 'WebkitTransition';

Exercise 2: Filter range

Write a function filterRange(arr, a, b) that gets an array arr, looks for elements with values higher or equal to a and lower or equal to b and return a result as an array.

For instance:

let arr = [5, 3, 8, 1];
let filtered = filterRange(arr, 1, 4);
alert( filtered ); // 3,1 (matching values)
// alert( arr ); // 5,3,8,1 (not modified)

Exercise 3: Filter range in place

Write a function filterRangeInPlace(arr, a, b) that gets an array arr and removes from it all values except those that are between a and b.

The test is: a ≤ arr[i] ≤ b.

The function should only modify the array. It should not return anything.

let arr = [5, 3, 8, 1];
filterRangeInPlace(arr, 1, 4); // removed the numbers except from 1 to 4
// alert( arr ); // [3, 1]

Exercise 4: Sort in decreading order

  let arr = [5, 2, 1, -10, 8];
  // ... your code to sort it in decreasing order
  // alert( arr ); // 8, 5, 2, 1, -10

Exercise 5: Copy and sort array

We have an array of strings arr. We’d like to have a sorted copy of it, but keep arr unmodified.

Create a function copySorted(arr) that returns such a copy.

 let arr = ["HTML", "JavaScript", "CSS"];
 let sorted = copySorted(arr);
 alert( sorted ); // CSS, HTML, JavaScript
 // alert( arr ); // HTML, JavaScript, CSS (no changes)

Exercise 6: Shuffle an array

Write the function shuffle(array) that shuffles (randomly reorders) elements of the array.

Multiple runs of shuffle may lead to different orders of elements. For instance:

let arr = [1, 2, 3];
shuffle(arr);
// arr = [3, 2, 1]
shuffle(arr);
// arr = [2, 1, 3]
shuffle(arr);
// arr = [3, 1, 2]
// ...

All element orders should have an equal probability.

For instance, [1,2,3] can be reordered as [1,2,3] or [1,3,2] or [3,1,2] etc, with equal probability of each case.

Exercise 7: Filter unique array members

Let arr be an array.

Create a function unique(arr) that should return an array with unique items of arr.

For instance:

function unique(arr) {
/* your code */
}
let strings = ["Hare", "Krishna", "Hare", "Krishna",
"Krishna", "Krishna", "Hare", "Hare", ":-O"
];
alert( unique(strings) ); // Hare, Krishna, :-O