CODEWITHSUNDEEP
javascriptangulartypescript
Brettyoke49
Brettyoke49

Reputation: 243

Typescript array of items from another const array (from official beginner tutorial)

I'm following the Angular tutorial located on https://angular.io/start. I got all the way through it and am trying to practice building for production locally, but when I build I get this error:

error TS2345: Argument of type 'any' is not assignable to parameter of type 'never'. this.items.push(product);

The 'product' being pushed to the items array is defined as such in the tutorial (in its own separate file, products.ts):

export const products = [ 
  {
    id: 1,
    name: 'Phone XL',
    price: 799,
    description: 'A large phone with one of the best screens'
  },  
  {
    id: 2,
    name: 'Phone Mini',
    price: 699,
    description: 'A great phone with one of the best cameras'
  },  
  {
    id: 3,
    name: 'Phone Standard',
    price: 299,
    description: ''
  }
];

Here is the file where I'm attempting to use it:

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

import { products } from './products';

@Injectable()

export class CartService {
  items = []; 

  constructor(
    private http: HttpClient
  ) {}

  addToCart(product) {
    this.items.push(product);
  }

  getItems() {
    return this.items;
  }

  clearCart() {
    this.items = []; 
    return this.items;
  }

  getShippingPrices() {
    return this.http.get('/assets/shipping.json');
  }
}

I've tried defining the items array in these ways, but all resulted in some error:

items = []

items : any[] = [];

items : {id: bigint, name: string, price: bigint, description, string}[] = [];

Any suggestions would be much appreciated.

Upvotes: 1

Views: 4973

Answers (2)

baumannalexj
baumannalexj

Reputation: 876

(I can't comment) could you expand the example and give the use case? This seems to work:

export const products = [ 
  {
    id: 1,
    name: 'Phone XL',
    price: 799,
    description: 'A large phone with one of the best screens'
  },  
  {
    id: 2,
    name: 'Phone Mini',
    price: 699,
    description: 'A great phone with one of the best cameras'
  },  
  {
    id: 3,
    name: 'Phone Standard',
    price: 299,
    description: ''
  }
];

const items = [];

this.items.push(products)

console.log(items)

Upvotes: 0

Kacper Biedka
Kacper Biedka

Reputation: 166

It would be useful is you could provide more code samples (where the item is coming from) but I think if you are working with an array of objects you should declare an object interface. In Typescript you can't really do it like this

items : {id: bigint, name: string, price: bigint, description, string}[]  = [];

For objects you should declare an interface

const product = {
  id: 2,
  name: 'essa',
  price: 700,
  description: ''
}

interface Item {
  id: number;
  name: string;
  price: number;
  description: string;
}

// Array of objects that have the structure of Item
const items: Item[] = [];

items.push(product);

You also need to make sure that the products array have the type set to Item[] as well.

Upvotes: 2

Related Questions