ts-class.ts

class A{
    a1: number;
    a2():void{
        console.log('a2')
    }
    constructor(a1: number){
        this.a1 = a1
    }
}
class B extends A{
    b1: string;
    b2():void{
        console.log('b2')
    }
    constructor(a1: number, b1: string){
        super(a1)
        this.b1 = b1
    }
}