打字稿键入已知的密钥和未知的密钥

Question

I want to declare an object that have at least some required keys , while the object may contain any other keys too.

For example, the object student must has the key name and gender , and any other keys are acceptable. How to declare the typing?

let student:{name:string, gender:string, ???};

//these must be valid
student = {
    name:'Goku',
    gender:'male',
    power:'Super Saiyan'
}

student = {
    name:'Pikachu',
    gender:'unknown',
    body:'yellow',
    shoeSize:20
}

I hardly found any tutorial related to this, it seems rare, may I know is this a bad practice? And why?

Answer 1

let student: {
  name:string;
  gender:string;
  [key: string]: any;
};

// these are valid
student = {
  name: 'Goku',
  gender: 'male',
  power: 'Super Saiyan'
};

student = {
  name: 'Pikachu',
  gender: 'unknown',
  body: 'yellow',
  shoeSize: 20
};

// this is invalid
student = {
  body: 'yellow',
  shoeSize: 20
};

Answer 2

Maybe declare an interface with name and gender. Then make your class a subclass of 'Any' that implements the interface.