Sort Array Of Objects By Id Javascript

Sort Array Of Objects By Id Javascript

4 min read Jun 20, 2024
Sort Array Of Objects By Id Javascript

Sorting an Array of Objects by ID in JavaScript

Sorting arrays of objects is a common task in JavaScript development. In this article, we'll explore how to sort an array of objects by their ID property using JavaScript's built-in sort method.

The sort method

The sort method is a built-in JavaScript array method that allows you to rearrange the elements of an array. It takes a comparison function as an argument, which determines the order of elements in the sorted array.

Sorting by ID

To sort an array of objects by their ID, we need to create a comparison function that compares the ID property of two objects. Here's an example:

const objects = [
  { id: 3, name: "Object 3" },
  { id: 1, name: "Object 1" },
  { id: 2, name: "Object 2" },
];

objects.sort((a, b) => {
  return a.id - b.id;
});

console.log(objects); // Output: [{ id: 1, name: "Object 1" }, { id: 2, name: "Object 2" }, { id: 3, name: "Object 3" }]

In this example:

  1. We define an array of objects called objects with each object containing an id and name property.

  2. We use the sort method on the objects array, passing in a comparison function.

  3. The comparison function takes two objects a and b as arguments. It subtracts the id of b from the id of a.

    • If the result is positive, a comes after b in the sorted array.
    • If the result is negative, a comes before b in the sorted array.
    • If the result is zero, the order of a and b remains unchanged.
  4. After sorting, we log the objects array, which now displays the objects in ascending order of their IDs.

Ascending vs. Descending Order

To sort in descending order, we simply reverse the order of subtraction in the comparison function:

objects.sort((a, b) => {
  return b.id - a.id;
});

Conclusion

Sorting arrays of objects by ID is a simple process using the sort method and a custom comparison function. By defining the comparison function correctly, you can achieve either ascending or descending order based on the ID property. This technique can be easily adapted to sort by other properties as well.