Angular - Can't assign null to File type-CodePudding

I have got an interface like this

export interface ReportFiles {
  ReportName: string;
  Log: number;
  MyFile: File;
}

And in my component, I declared the object as

export class MyComponent Implements OnInit {
  RF:  ReportFiles = { ReportName: "", Log: 0, MyFile: null }
  ...
  ...
}

The error message shows

'null' is not assignable to File

How can I resolve this?

CodePudding user response：

Specify MyFile with nullable type.

interface ReportFiles {
  ReportName: string;
  Log: number;
  MyFile?: File | null;
}

Sample Demo on Typescript Playground

CodePudding user response：

We usually don't assign type any because it defeats the purpose of type checking but any type may be used when type changes are expected.

export interface ReportFiles{
  ReportName: string;
  Log: number;
  MyFile: any;
}

Seeing your need to initialize a obj RF type of ReportFiles I would suggest converting ReportFiles and File into class objects. But this is optional. If you need/wish to create an instance of perhaps a custom object, whilst getting the benefits of type-checking things such as arguments, return types or generics - a class makes sense. If you’re not creating instances - we have interfaces at our disposal, and their benefit comes from not generating any source code, yet allowing us to somewhat “virtually” type-check our code.