Sorting Arrays of Integers in JavaScript

In JavaScript, sorting arrays of integers can be a bit tricky if you’re not aware of the default behavior of the sort() method. By default, sort() sorts elements alphabetically, which means it treats numbers as strings. This can lead to unexpected results when sorting arrays of integers.

To sort an array of integers correctly, you need to provide a compare function that tells JavaScript how to compare two numbers. The compare function should return a value that determines the order of the two numbers being compared. If the result is negative, a comes before b. If the result is positive, b comes before a. If the result is 0, the order of a and b remains unchanged.

Here’s an example of how to sort an array of integers using a compare function:

var numArray = [140000, 104, 99];
numArray.sort(function(a, b) {
  return a - b;
});
console.log(numArray); // Output: [99, 104, 140000]

In this example, the compare function function(a, b) { return a - b; } is used to sort the array in ascending order. You can also use an arrow function to define the compare function inline:

numArray = numArray.sort((a, b) => a - b);

Note that the sort() method sorts the array in place, meaning it modifies the original array. Therefore, you don’t need to assign the result back to the original variable.

It’s also worth noting that if your array contains Infinity or NaN values, you should use a more robust compare function to handle these cases correctly. According to the Mozilla documentation, using return a - b is recommended for arrays that don’t contain Infinity or NaN, since Infinity - Infinity returns NaN, not 0.

In addition to using a compare function, you can also use TypedArrays to sort arrays of integers. However, this approach may be slower than using a compare function:

var numArray = new Float64Array([140000, 104, 99]);
numArray = numArray.sort();
console.log(numArray);

In summary, to sort an array of integers in JavaScript, you should provide a compare function that tells JavaScript how to compare two numbers. You can use the sort() method with a compare function or an arrow function to define the compare function inline.