TypeScript Challenges

A collection of short challenges to get used to coding with TypeScript.

Each challenge is designed to help you solve some common real-life problems. By the end of the challenges, you will have a collection of functions that can be used in your own projects.

Getting started

The easiest place to try out this code is in the online TypeScript playground. Be aware that your code will not save here. Once you have completed a challenge, copy and save the code somewhere on your machine for future reference.

You will need to use your online research skills to find solutions to these problems. Think carefully about how you will word your searches to get the best results returned to you.

The code challenges

1. minValue() and maxValue()

Write two functions: minValue and maxValue. Both functions should take an array of numbers as an argument and return the lowest and highest numbers respectively. E.g.

const numbers = [34, 12, 4, 9, 1265, 2];

console.log(minValue(numbers)); // -> 2
console.log(maxValue(numbers)); // -> 1265

2. sumArrayValues()

Write a function called sumArrayValues that takes an array of numbers as an argument. It should return the sum of all the numbers in the array, regardless of how many numbers it contains.

console.log(sumArrayValues([1, 1, 1])); // -> 3
console.log(sumArrayValues([1, 2, 3])); // -> 6
console.log(sumArrayValues([1, 2, 3, 4, 5])); // -> 15
console.log(sumArrayValues([])); // -> 0

3. titleCase()

The titleCase() function should take a string as an argument, and return a new string where every word starts with a capital letter.

console.log(titleCase("I'm a little teapot")); // "I'm A Little Teapot"
console.log(titleCase("SHORT AND STOUT")); // "Short And Stout"
console.log(titleCase("hERe's My hAnDlE")); // "Here's My Handle"
console.log(titleCase("here's my spout")); // "Here's My Spout"

4. truncateString()

truncateString() should take an object as an argument that contains two attributes: text which is a string, and maxChars which is an optional number value. maxChars should be set to a default value of 10.

It should return a string. If the text passed into the function has more characters than the maxChars value, any characters beyond this value should be replaced with an ellipsis ('...'). E.g.

console.log(truncateString({ text: "Hello!" })); // -> "Hello!"
console.log(truncateString({ text: "Hello World!" })); // -> "Hello Worl..."
console.log(truncateString({ text: "Hello World!", maxChars: 20 })); // "Hello World!"
console.log(
  truncateString({ text: "Hello World! How are we today?", maxChars: 20 })
); // "Hello World! How are..."

5. slugify()

The slugify() function should take a string and return a URL friendly, 'slugified' version of it that is in lower case and has any spaces between words replaced with dashes:

console.log(slugify("Hello World")); // -> "hello-world"
console.log(slugify("HELLO WORLD HOW ARE YOU")); // -> "hello-world-how-are-you"

🚀 EXTRA CREDIT 1

Remove any white space from the start and end of the string:

console.log(slugify("    HELLO WORLD HOW ARE YOU  ")); // -> "hello-world-how-are-you"

🚀🚀 EXTRA CREDIT 2

Remove any non-alphanumeric characters (i.e. characters that are not letters or numbers) from the slugified string:

console.log(slugifySecondCredit("  What's TypeScript all about?    ")); // -> "whats-typescript-all-about"

Good luck! 🤓