Static Typing

Typescript allows you to specify types for variables, parameters, return types and more. This helps type-related errors during development.

let age: number = 30;
let name: string = "foo";
let isDev: boolean = true;

function add(x:number, y:number):number{return x+y}

Interfaces

Interfaces define the structure of objects

interface Person {
    name: string;
    age: number;
}

function greet(person: Person): void {
    console.log(`Hello, ${person.name}!`);
}

let user = { name: "foo", age: 25 };
greet(user);

Classes and inheritance

Typescript supports classes and inheritance

class Fruit{
    //properties
    name:string;
    color:string;

    // constructor
    constructor(name:string, color:string){
        this.name = name;
        this.color = color;
    }

    // Method
    describe():string{
        return `This ${this.name} is ${this.color}`;
    }

}

// subClass
class Appple extends Fruit{
    //additional property
    taste: string;

    // constructor
    constructor(name:string, color:string, taste: string){
        super(name, color);
        this.taste = taste;
    }
    // Override method
    describe():string{
        return `${super.describe()} It tastes ${this.taste}.`;
    }
}
// create instance
const apple = new Apple("Apple", "red", "sweet");