How to implement full cart system in Ionic 3?

Hello I have just created a cart system following https://www.joshmorony.com/add-to-cart-with-the-web-animations-api-in-ionic/ tutorial. I might be doing some silly mistake or my logic might be wrong. When I add same product multiple times /another element is created in object rather then modifying just the quantity of that particular element. please help… Here is my Home.ts

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { ListPage } from '../list/list';

@Component({
selector: 'page-home',
templateUrl: 'home.html'
})
export class HomePage {

items : Object[] = [];
itemsInCart: Object[] = [];

constructor(public navCtrl: NavController) {

this.items = [
{ 'name': 'Hello World', quantityInCart: 0 , id: 1},
{ 'name': 'Hello1 World', quantityInCart: 0 , id: 2},
{ 'name': 'Hello2 World', quantityInCart: 0 , id: 3},
{ 'name': 'Hello3 World', quantityInCart: 0 , id: 4}
];
}

addToCart(item) {
item.quantityInCart += 1;
this.itemsInCart.push(item); 
console.log(this.itemsInCart);

localStorage.setItem('cart', JSON.stringify(this.itemsInCart));
}

goToList() {
this.navCtrl.push(ListPage);
}

}


output

I want the output to be

[{…}]0: {name: “Hello World”, quantityInCart: 2, id: 1}

Your addToCart method has to go through the items already in the cart an update those instead of adding an additional item.

yes, but something is not done correctly. Can you please some code example…