Natural Order Sorting

Part of the Logic & Flow section of Coddy's PHP journey — lesson 24 of 68.

While PHP's standard sorting functions work well for most cases, they can produce unexpected results when sorting strings that contain numbers. The natsort() function solves this problem by using a "natural ordering" algorithm that sorts strings the way humans would naturally expect.

Consider this example with file names:

<?php
$files = ["file1.txt", "file10.txt", "file2.txt", "file20.txt"];

// Regular sort() produces: file1.txt, file10.txt, file2.txt, file20.txt
sort($files);
print_r($files);

// Reset the array
$files = ["file1.txt", "file10.txt", "file2.txt", "file20.txt"];

// natsort() produces: file1.txt, file2.txt, file10.txt, file20.txt
natsort($files);
print_r($files);
?>

The difference is crucial: regular sort() compares strings character by character, so "file10.txt" comes before "file2.txt" because "1" comes before "2" in ASCII. However, natsort() recognizes the numeric portions and sorts them numerically, placing "file2.txt" before "file10.txt" as you would naturally expect.

Like other PHP sorting functions, natsort() modifies the original array directly. This makes it particularly useful for organizing file listings, version numbers, or any data where strings contain embedded numbers that should be sorted numerically rather than alphabetically.

Challenge

Easy

You will receive one input: an array of software version numbers in JSON format. Read the input, convert the JSON string to an array, use natsort() to sort the version numbers in natural order, and print the sorted array using print_r().

Input format: One line containing a JSON array of version strings (example: ["v1.10","v1.2","v1.20","v1.3"])

Expected output: The sorted array in natural order, displayed using print_r()

Try it yourself

<?php
// Read input
$input = fgets(STDIN);

// Convert JSON string to array
$versions = (array)json_decode($input, true);

// TODO: Write your code below to sort the array using natsort()


// Output the sorted array
print_r($versions);
?>