# Creating a Service — Angular

Source: https://www.geekswithgeeks.com/en/angular/ng-services-intro

> Pull shared logic and state out of components.

## @Injectable

A **service** is a plain class marked `@Injectable` that holds logic or state you don't want duplicated in every component.

```typescript
import { Injectable } from '@angular/core';

@Injectable({ providedIn: 'root' })
export class CartService {
  private items: string[] = [];

  add(item: string) {
    this.items.push(item);
  }

  getItems() {
    return this.items;
  }
}
```

## providedIn: 'root'

`providedIn: 'root'` registers the service as a single app-wide **singleton** — the same instance is shared everywhere it's injected.