How to Best Sort an Array of Objects by Property or Method?

Question

I am writing a function that will sort an array of objects either by property or method value. The following code is working. But how do I improve it? I feel there is a lot of duplicate code in it.

 transform(array: any, field: string): any[] {
  if (!Array.isArray(array)) {
    return;
  }
  array.sort((a: any, b: any) => {
    if (typeof a[field] == 'function' && typeof b[field] == 'function') {
      if (a[field]() < b[field]()) {
        return -1;
      } else if (a[field]() > b[field]()) {
        return 1;
      } else {
        return 0;
      }
    }
    if (a[field] < b[field]) {
      return -1;
    } else if (a[field] > b[field]) {
      return 1;
    } else {
      return 0;
    }
  });
  return array;
}

Go to the Code review site

Ele
– Ele

2020-08-27 14:42:53 +00:00
Commented Aug 27, 2020 at 14:42 — Ele
– Ele, Commented Aug 27, 2020 at 14:42
You could use lodash sortBy lodash.com/docs/4.17.15#sortBy

MoxxiManagarm
– MoxxiManagarm

2020-08-27 14:57:17 +00:00
Commented Aug 27, 2020 at 14:57 — MoxxiManagarm
– MoxxiManagarm, Commented Aug 27, 2020 at 14:57

Jonas Wilms · Accepted Answer · 2020-08-27 14:44:13Z

1

  const callOrTake = it => typeof it === "function" ? it() : it;  
  const compare = (a, b) => a === b ? 0 : (a > b ? 1 : -1); 
  const transform = <T> (array: T[], field: keyof T) => array.sort((a, b) => compare(callOrTake(a[field]), callOrTake(b[field])));

The following improvements were made:

(1) Calling the field if it is a function was moved to it's own function to avoid repetition.

(2) The signature of transform was improved so that field cannot be any string, but has to be a key of whatever is inside the array.

answered Aug 27, 2020 at 14:44

Jonas Wilms

139k20 gold badges164 silver badges164 bronze badges

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

1 Comment

Rayhan Muktader Over a year ago

I was trying to build an Angular Pipe. It would seem that both compare and callOrTake are inaccessible from the anonymous function inside sort. IDK but that just might have something do with Angular. I am still going to accept your answer bcz it has all the necessary elements for improving the original code.

Collectives™ on Stack Overflow

How to Best Sort an Array of Objects by Property or Method?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related