Property does not exist on type, when it clearly does

I'm writing my code in Typescript, and I'm trying to access property named id on any object that implements an interface named ObjectTemplate.

Let's say I have an class Player, that implements ObjectTemplate, that has an id property. Then, I pass new Player() into addObject() function I have provided below.

When I try to access the new Player().id (or as I named it in my parameter, obj.id), I get an error telling me that Property 'id' does not exist on type 'ObjectTemplate'

interface ObjectTemplate {      id: string  }    class Player implements ObjectTemplate {      id: string      name: string            constructor(name: string) {          this.name = name      }  }    class Entity implements ObjectTemplate {      id: string      health: number            constructor(health: number) {          this.health = health      }  }    const createId = () => 'randomId'      class ObjectList<ObjectTemplate> {      objects: { [key: string]: ObjectTemplate }        constructor() {          this.objects = {}      }        addObject(obj: ObjectTemplate) {          const newId = createId()                    obj.id = newId // I get an error here.                    this.objects[newId] = obj      }  }    const playerList: ObjectList<Player> = new ObjectList()  playerList.addObject(new Player("someName"))    const entityList: ObjectList<Entity> = new ObjectList()  entityList.addObject(new Entity(100))  

Playground

https://stackoverflow.com/questions/66700483/property-does-not-exist-on-type-when-it-clearly-does March 19, 2021 at 07:20AM