Refer these for inheritance and more...🎈

BasicPhone.ts

import { Mobile } from "./Mobile";

export class BasicPhone extends Mobile{
    mobileType:string;

    constructor(mobileName:string,mobileCost:number,mobileId: number,mobileType:string){
        super(mobileId, mobileName, mobileCost);
        this.mobileType=mobileType;
    }
    
    printMobileDetails = ()=> console.log("Mobile Name: "+ this.mobileName+", "+"Mobile cost "+this.mobileCost+", "+"Mobile Type: "+this.mobileType);
    
}


 

Demo.ts

import { BasicPhone } from "./BasicPhone";
import { SmartPhone } from "./SmartPhone";



let mobileArray:(BasicPhone | SmartPhone)[] = [new BasicPhone("Karbon",1500,2,"Flat"), new SmartPhone("Samsung",500,5,"Slim")];
/*

for (const key of mobileArray) {
	console.log(key.printMobileDetails());
}
? Lets do this using forEach
*/

mobileArray.forEach(element => {
	element.printMobileDetails();
});

Mobile.ts

export class Mobile {
    mobileId: number;
    mobileName: string;
    mobileCost: number;
    
    constructor(mobileId: number, mobileName: string, mobileCost: number) {
        this.mobileCost = mobileCost;
        this.mobileId = mobileId;
        this.mobileName = mobileName;
    }

}

SmartPhone.ts

import { Mobile } from "./Mobile";

export class SmartPhone extends Mobile{
    mobileType:string;

    constructor(mobileName:string,mobileCost:number,mobileId: number,mobileType:string){
        super(mobileId, mobileName, mobileCost);
        this.mobileType=mobileType;
    }
    // My Arrow ==> way of dealing with stuff
    printMobileDetails = ()=>console.log("Mobile Name: "+ this.mobileName+", "+"Mobile cost "+this.mobileCost+", "+"Mobile Type: "+this.mobileType);
    
}