Sorting objects based on a string value property in TypeScript

Question

I have an array of objects and the definition for an object looks something like this:

export class AccountInfo {
  accountUid: string;
  userType: string;
  firstName: string;
  middleName: string;
  lastName: string;
}

NOTE: The reason I don't have userType as an enum is because the object is populated by a database call and I couldn't figure out a clean way to have the string returned from the db populate the enum.

I want to sort the array so that objects with a userType of 'STAFF' appear first, followed by 'TEACHER', then 'PARENT', then 'STUDENT'.

Answer 1

You can store the order in an array, then just use indexOf with sort to achieve your goal. See the code example below:

const humans = [{
  accountUid: "1",
  userType: "TEACHER",
}, {
  accountUid: "2",
  userType: "STAFF",
}, {
  accountUid: "3",
  userType: "STUDENT",
}, {
  accountUid: "4",
  userType: "PARENT",
}];

const order = ['STAFF', 'TEACHER', 'PARENT', 'STUDENT'];

const result = humans.sort((a, b) => order.indexOf(a.userType) - order.indexOf(b.userType));

console.log(result)

If you can't use ES6, just use:

humans.sort(function(a, b){
    return order.indexOf(a.userType) - order.indexOf(b.userType);
});