# How to sort an array of numbers in JavaScript?

Published October 29, 2020

To sort an array of `numbers` in JavaScript, you can use the `sort()` method on the array object.

## Sort the array in ascending order

To sort the `numbers` array in ascending order, you have to pass a function to the `sort()` method to customize its behavior, and the function will be passed 2 elements `a` and `b` while iterating.

You have to subtract `a-b` and return the result.

``````// array of numbers
const numArr = [34, 56, 78, 90, 4, 5, 6, 34];

// sort array
// in ascending order
numArr.sort((a, b) => {
return a - b;
});

console.log(numArr); // [4, 5, 6, 34, 34, 56, 78, 90]``````

Here `a` is the second element of the current iteration and `b` is the first element of the current iteration.

If the result of the subtraction is a negative number, then the numbers are swapped and the array contains numbers in ascending order.

See this example live in JSBin.

## Sort the array in descending order

To sort the `numbers` array in ascending order, you have to pass a function to the `sort()` method to customize its behavior, and the function will be passed 2 elements `a` and `b` while iterating.

You have to subtract `b-a` and return the result.

``````// array of numbers
const numArr = [34, 56, 78, 90, 4, 5, 6, 34];

// sort array
// in descending order
numArr.sort((a, b) => {
return b - a;
});

console.log(numArr); // [90, 78, 56, 34, 34, 6, 5, 4]``````

Here `a` is the second element of the current iteration and `b` is the first element of the current iteration.

If the result of the subtraction is a negative number, then the numbers are swapped and the array contains numbers in descending order.

See this example live in JSBin.