how to create an interface in typescript code example

Example 1: typescript class interface

interface IPerson {
  name: string
  age: number
  hobby?: string[]
}

class Person implements IPerson {
  name: string
  age: number
  hobby?: string[]

  constructor(name: string, age: number, hobby: string[]) {
    this.name = name
    this.age = age
    this.hobby = hobby
  }
}

const output = new Person('john doe', 23, ['swimming', 'traveling', 'badminton'])
console.log(output)

Example 2: typescript class implements interface

interface Task{
    name: String; //property
    run(arg: any):void; //method
}

class MyTask implements Task{
    name: String;
    constructor(name: String) {
        this.name = name;
    }
	run(arg: any): void {
        console.log(`running: ${this.name}, arg: ${arg}`);
    }
}

let myTask: Task = new MyTask('someTask');
myTask.run("test");

Example 3: typescript interface

interface NumberOrStringDictionary {
  [index: string]: number | string;
  length: number; // ok, length is a number
  name: string; // ok, name is a string
}Try

Example 4: ts extends

class Animal {
    name: string;
    constructor(theName: string) { this.name = theName; }
    move(distanceInMeters: number = 0) {
        console.log(`${this.name} moved ${distanceInMeters}m.`);
    }
}

class Snake extends Animal {
    constructor(name: string) { super(name); }
    move(distanceInMeters = 5) {
        console.log("Slithering...");
        super.move(distanceInMeters);
    }
}

class Horse extends Animal {
    constructor(name: string) { super(name); }
    move(distanceInMeters = 45) {
        console.log("Galloping...");
        super.move(distanceInMeters);
    }
}

let sam = new Snake("Sammy the Python");
let tom: Animal = new Horse("Tommy the Palomino");

sam.move();
tom.move(34);