How to Sort JavaScript Objects by Key?

How to Sort JavaScript Objects by Key

Sorting JavaScript objects by key can be a useful technique for manipulating data and ensuring its consistency. In JavaScript, objects are unordered by default, meaning that the keys are not arranged in any particular order. However, there are ways to sort and rearrange the keys of an object.

The ES6 specification introduced ordered property iteration, which provides a guaranteed order for accessing object properties. Object.keys(object) returns an array of the object's keys, and this array can be sorted using the sort() method.

To implement this sorting, follow these steps:

1. Convert the object to an array of its keys using Object.keys(object).
2. Sort the array using the sort() method.
3. Create a new object and iterate through the sorted array, adding each key-value pair to the new object. This ensures the new object has keys sorted in the specified order.

const unordered = {
  b: 'foo',
  c: 'bar',
  a: 'baz'
};

console.log(JSON.stringify(unordered)); // → '{"b":"foo","c":"bar","a":"baz"}'

const ordered = Object.keys(unordered).sort().reduce(
  (obj, key) => { 
    obj[key] = unordered[key]; 
    return obj;
  }, 
  {}
);

console.log(JSON.stringify(ordered)); // → '{"a":"baz","b":"foo","c":"bar"}'

Using this approach, you can easily sort JavaScript objects by key and preserve the order of the sorted keys in the new object. This technique can prove useful in various situations, such as when you need to consistently iterate over object properties, display data in a specific order, or compare object keys for equality checks.

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