JSON.stringify ignores properties in custom class when it is not declared in constructor

Question

I defined a class:

export class SavedData{
    public isDone : boolean;
}

and try to stringify it:

console.log(new SavedData());

but it doesn't include the isDone property

{}

,which I need to move isDone to constructor:

export class SavedData{
  constructor(public isDone : boolean){
  }
}

to be successful:

{"isDone":false}

why would it happen? and is it possible to stringify a class property without declaring it into constructor?

Günter Zöchbauer · Accepted Answer · 2016-11-16 08:00:42Z

1

It's working if you initialize it with a default value

export class SavedData{
    public isDone : boolean = null; // or = false;
}

answered Nov 16, 2016 at 8:00

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