Let's Sort it out.

Today, we will go through how to sort arrays in javascript, this is the 4'th article in this mini array log series i'm doing, you can read the other 3 to familiarize yourself with arrays, but if you just want to learn how to sort your arrays you can keep reading (assuming you are already familiar with array basics).

Sorting Arrays.

The sort method sorts arrays alphabetically.

const names = ['Simon', 'Gichohi', 'Njogu'];

console.log(names.sort());

Reversing Array.

The reverse method, reverses the elements in an array.

const names = ['Simon', 'Gichohi', 'Njogu'];

console.log(names.reverse());

Numeric Sort

The sort function does not sort numbers correctly. Here is where we now use the compare function, it's purpose is to define an alternative sort order.

The compare function should return a negative, zero or positive value, depending on the argumentsz.

When the sort() function compares two values, it sends the values to the compare function, and sorts the values according the returned (negative, zero, positive) value.

if the result is negative a is sorted before b and if the result is positve b is sorted before a, lastly, if the result is 0 no changes are done with the sort order of the two values.

Example

const points = [40, 100, 1, 5, 25, 10];

console.log(
  points.sort(function (a, b) {
    return a - b;
  })
);

The compare function compares all the values in the array, two values at a time (a, b).

When comparing 40 and 100, the sort() method calls the compare function (40, 100).

The function calculates 40 - 100 (a - b), and since the result is negative, the sort function will sort 40 as a value lower than 100.

Sorting numbers in descending order.

const points = [40, 100, 1, 5, 25, 10];

console.log(
  points.sort(function (a, b) {
    return b - a;
  })
);

Sorting Arrays in Random Order.

const points = [40, 100, 1, 5, 25, 10];

console.log(
  points.sort(function (a, b) {
    return 0.5 - Math.random();
  })
);

Conclusion.

We went through the basics of sorting arrays but we are only half way through, in my next two blogs, we will go through other ways of sorting the minimum and maximum, and also the fisher yates method, These are more complex but i will do my best to simplify them.

Happy Sorting nerds 🤗