How to specify an interface type to an object element in TypeScript?

Question

I want to specify an interface to my object like this:

interface Item {
    id: number;
    size: number;
}


var obj  = {
    name: "test",
    items:Item = null 
}

and I want to assign obj.items some value after I fetched some data from server on ngOninit().

is that possible?

var obj: { name: string, items: Item | null } = { ... }? Or you could use items?: Item and default to undefined, either implicitly or explicitly. — jonrsharpe
– jonrsharpe, Commented Jun 24, 2019 at 11:20

Arun Selva Kumar · Accepted Answer · 2019-06-25 10:03:52Z

2

Construction of Type

interface Item {
    id: number;
    size: number;
}

interface ParentItem {
    name: string;
    item: Item | null;
}

Construction of Object:

let object: ParentItem = { name: "test", item: null };

edited Jun 25, 2019 at 10:03

answered Jun 24, 2019 at 11:28

Arun Selva Kumar

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3 Comments

jonrsharpe Over a year ago

Despite the acceptance note that the construction example is neither: 1. valid syntax; nor 2. type safe.

Arun Selva Kumar Over a year ago

@jonrsharpe updated the syntax, I am not sure to understand about type safety.

jonrsharpe Over a year ago

You say it is always an Item then set it to null. Either make it nullable or optional.

Deepika chalana · Accepted Answer · 2019-06-24 11:32:56Z

0

export interface ClientEmployee {
clientTeamID: number;
employeeID: number;
sharingPercent: number;
}
import 
 ClientEmployees = {
id: 0,
clientTeamID: 0,
employeeID: 0,
sharingPercent: 0,
clientName: ''
  };
 get in oninit 

 this.restService.GetTeamEmployees('').subscribe(response => {
  if (response.error == null && response.message === 'Success' && 
 response.data.length > 0) {
    this.ClientEmployees = response.data;
    this.loaderService.hide();
    }  });

answered Jun 24, 2019 at 11:32

community wiki

Deepika chalana

1 Comment

jonrsharpe Over a year ago

What does this even mean?

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