PHP Array Sorting

Sorting arrays is a fundamental task in programming. PHP provides several functions to sort array elements in different ways, whether they are indexed or associative.

1. Sorting Indexed Arrays

For indexed arrays (arrays with numeric keys), you use sort() for ascending order and rsort() for descending order.

Sort in Ascending Order - sort()

<?php
    $fruits = ["Cherry", "Apple", "Banana"];
    sort($fruits);
    // Result: ["Apple", "Banana", "Cherry"]
?>

Sort in Descending Order - rsort()

<?php
    $numbers = [4, 2, 8, 6];
    rsort($numbers);
    // Result: [8, 6, 4, 2]
?>

2. Sorting Associative Arrays

When sorting associative arrays, you must decide if you want to sort by Value or by Key, and whether to maintain the key-value relationship.

Sort by Value (Ascending) - asort()

Maintains the index association (Peter is still 35).

<?php
    $age = ["Peter"=>"35", "Ben"=>"37", "Joe"=>"43"];
    asort($age);
?>

Sort by Key (Ascending) - ksort()

<?php
    $age = ["Peter"=>"35", "Ben"=>"37", "Joe"=>"43"];
    ksort($age);
?>

Sorting Functions Reference

Key Points

• Ascending: sort, asort, ksort.
• Descending: rsort, arsort, krsort.
• Values: sort, asort.
• Keys: ksort, krsort.
• The 'a' in asort stands for **associative** (maintains associations).