Sorting Array of Objects

An array of objects is a collection of objects. Consider the following array of objects:

const items = [

  { name: "Alpha", value: 23 },
  { name: "Bravo", value: 42 },
  { name: "Echo", value: 31 },
  { name: "Foxtrot", value: 56 },
  { name: "Charlie", value: 17 },
  { name: "Delta", value: -9 },

];

To sort the array based on the `value` property, use the `.sort()` method with a comparator function:

items.sort((a, b) => a.value - b.value);

const items = [

  { name: "Delta", value: -9 },
  { name: "Charlie", value: 17 },
  { name: "Alpha", value: 23 },
  { name: "Echo", value: 31 },
  { name: "Bravo", value: 42 },
  { name: "Foxtrot", value: 56 },

];

In this example, the comparator function `(a, b) => a.value - b.value` compares the `value` properties of two objects in the `items` array:

• If `a.value` is more than `b.value`, the function returns a positive value meaning `a` should come after `b`.
• If `a.value` is less than `b.value`, the function returns a negative value meaning `a` should come before `b`.
•  If `a.value` is equal to `b.value`, the function returns zero meaning `a` and `b` are equal in order.

If we wanted to sort the array in descending order based on the `value` property, then we would use the `.sort()` as

items.sort((a, b) => b.value - a.value);

After running the above snippet the items array will be sorted as:

const items = [

  { name: "Foxtrot", value: 56 },
  { name: "Bravo", value: 42 },
  { name: "Echo", value: 31 },
  { name: "Alpha", value: 23 },
  { name: "Charlie", value: 17 },
  { name: "Delta", value: -9 },

];

Takeaways / Best Practices:

• Be mindful of potential edge cases, such as handling `NaN` or `Infinity` values, if they exist in the array.
• Always consider the specific sorting requirements and adjust the compare function accordingly.

Here are a few problems where these concepts are used:

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