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'.

Dan Cantir · Accepted Answer · 2019-10-30 14:00:20Z

13

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);
});

edited Oct 30, 2019 at 14:00

answered Apr 22, 2017 at 21:40

Dan Cantir

2,96517 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Sumi Straessle Over a year ago

Elegant way to do it.

TovrikTheThird Over a year ago

This was exactly what I was looking for, thanks! I noticed a few other responses to this question originally that were less elegant but after seeing this solution they must have removed their posts. Either way, this was not only a good and efficient solution, but your answer was very thorough thanks to the use of mock data. Props to you sir/madame!

sunny arya Over a year ago

doesn't work for me. It says that boolean cannot be converted to number.

solecoder · Accepted Answer · 2021-05-10 17:55:01Z

0

Here is another way to do it, probably have an order object to store the orders

const actionOrder = {
    "EAT" : 1,
    "SLEEP" : 2,
    "PLAY" : 3,
} as const;

const users = [{
    name: "Mike",
    action: "PLAY"
}, {
    name: "John",
    action: "EAT"
}, {
    name: "Harry",
    action: "SLEEP"
}
];

users.sort((a,b) => {
    return actionOrder[a.action] - actionOrder[b.action];
});

console.log(users);

answered May 10, 2021 at 17:55

solecoder

2314 silver badges13 bronze badges

Collectives™ on Stack Overflow

Sorting objects based on a string value property in TypeScript

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related