Sorting in PHP

PHP doesn’t have a built-in sorting package like Go’s slices package, but we can use PHP’s built-in sorting functions to achieve similar functionality. Here’s how we can implement sorting in PHP:

<?php

// PHP's sorting functions work directly on arrays.
// We'll define our arrays and then sort them.

// Sorting strings
$strs = ["c", "a", "b"];
sort($strs);
echo "Strings: " . implode(", ", $strs) . "\n";

// Sorting integers
$ints = [7, 2, 4];
sort($ints);
echo "Ints:    " . implode(", ", $ints) . "\n";

// We can also check if an array is sorted
function isSorted($arr) {
    return $arr == sort($arr);
}

$sorted = isSorted($ints);
echo "Sorted:  " . ($sorted ? "true" : "false") . "\n";

PHP’s sorting functions are not generic like in some other languages. Instead, PHP provides different functions for different types and sorting needs:

1. sort(): Sorts an array in ascending order.
2. rsort(): Sorts an array in descending order.
3. asort(): Sorts an associative array in ascending order, according to the value.
4. ksort(): Sorts an associative array in ascending order, according to the key.

These functions modify the original array directly, rather than returning a new sorted array.

To check if an array is sorted, we’ve created a simple isSorted() function. It compares the original array with a sorted version of itself.

To run this program, save it as sorting.php and execute it with PHP:

$ php sorting.php
Strings: a, b, c
Ints:    2, 4, 7
Sorted:  true

This example demonstrates basic sorting operations in PHP. For more complex sorting needs, PHP also provides usort(), uasort(), and uksort() functions that allow you to define custom comparison functions.