Learn Primitives Types in TypeScript

Hello there 👋! I am Birusha Ndegeya.

Learning TypeScript is crucial to understanding programming languages. TypeScript, being a superset of JavaScript, can be easily learned if you're familiar with JavaScript fundamentals. You can even choose TypeScript as your first programming language.

In this tutorial, we'll cover the basics of TypeScript, starting with data types. For those new to programming, knowing how to print something on a computer using TypeScript is essential. Let's start with a basic command:

console.log("Hello World"); // Output: Hello World

Let's dive deeper into understanding TypeScript primitive types.

To create a variable, we use the keywords let or const.

let name: string = "Jill";
const ID: number = 1;

To display these variables, we use the function:

console.log(name); // Output: Jill
console.log(ID); // Output: 1

We use const for values that never change, and by convention, we write them in uppercase. let is used when the value can change.

Now, let's explore the basic data types widely used in TypeScript:

• string : Represents a chain of characters enclosed in double or single quotes.

let firstName: string = "Jimmy";
let lastName: string = 'Elijah';
// We can print them to the screen:
console.log(firstName); // Output: Jimmy
console.log(lastName); // Output: Elijah

// Checking the type:
console.log(typeof firstName); // Output: string
console.log(typeof lastName); // Output: string

• boolean : Represents true or false values.

const isMale: boolean = true;
const isFemale: boolean = false;

// Printing them to the screen:
console.log(isMale); // Output: true
console.log(isFemale); // Output: false

// Checking the type:
console.log(typeof isMale); // Output: boolean
console.log(typeof isFemale); // Output: boolean

• number Represents any numeric value, including whole numbers or decimal numbers.

let age: number = 30;
const GPA: number = 3.1;

// Printing them to the screen:
console.log(age); // Output: 30
console.log(GPA); // Output: 3.1

// Checking the type:
console.log(typeof age); // Output: number
console.log(typeof GPA); // Output: number

Additionally, a variable can hold multiple types:

let ID: number | string;
// Assigning it a number value:
ID = 1;
console.log(ID); // Output: 1
// Checking the type:
console.log(typeof ID); // Output: number

// Assigning it a string value:
ID = '01';
console.log(ID); // Output: 01

// Checking the type:
console.log(typeof ID); // Output: string

Now, if you need a starter code, you can visit my GitHub profile.

Thanks for keeping up with the reading.

Happy coding! 🚀🚀🚚🚚🚚