typescript extend interface

1//declare interface to be extended
2interface Vehicle {
3  brand: string;
4  plateNumber: number;
5}
6
7interface Car extends Vehicle {}

1interface Task{
2    name: String; //property
3    run(arg: any):void; //method
4}
5
6class MyTask implements Task{
7    name: String;
8    constructor(name: String) {
9        this.name = name;
10    }
11	run(arg: any): void {
12        console.log(`running: ${this.name}, arg: ${arg}`);
13    }
14}
15
16let myTask: Task = new MyTask('someTask');
17myTask.run("test");

1interface Animal {
2  name: string
3}
4interface Bear extends Animal {
5  honey: boolean
6}
7const bear = getBear() 
8bear.name
9bear.honey
10        

1class Animal {
2    name: string;
3    constructor(theName: string) { this.name = theName; }
4    move(distanceInMeters: number = 0) {
5        console.log(`${this.name} moved ${distanceInMeters}m.`);
6    }
7}
8
9class Snake extends Animal {
10    constructor(name: string) { super(name); }
11    move(distanceInMeters = 5) {
12        console.log("Slithering...");
13        super.move(distanceInMeters);
14    }
15}
16
17class Horse extends Animal {
18    constructor(name: string) { super(name); }
19    move(distanceInMeters = 45) {
20        console.log("Galloping...");
21        super.move(distanceInMeters);
22    }
23}
24
25let sam = new Snake("Sammy the Python");
26let tom: Animal = new Horse("Tommy the Palomino");
27
28sam.move();
29tom.move(34);