The sort() function in PHP is used to sort indexed arrays in ascending order. It reindexes the array numerically (starting from 0), and modifies the original array.

🔧 Syntax

sort(array &$array, int $flags = SORT_REGULAR): bool

• $array: The array you want to sort (passed by reference).
• $flags (optional): Controls how the sorting is done. Common flags include:
  • SORT_REGULAR (default) – Compare items normally.
  • SORT_NUMERIC – Compare items numerically.
  • SORT_STRING – Compare items as strings.

🧪 Basic Example

$fruits = ["banana", "apple", "mango", "orange"];
sort($fruits);

print_r($fruits);

Output:

Array
(
    [0] => apple
    [1] => banana
    [2] => mango
    [3] => orange
)

🔢 Numeric Sorting Example

$numbers = [10, 3, 50, 23, 7];
sort($numbers);

print_r($numbers);

Output:

Array
(
    [0] => 3
    [1] => 7
    [2] => 10
    [3] => 23
    [4] => 50
)

🔤 String Sorting (Case-sensitive)

$names = ["Zack", "john", "Anna", "bob"];
sort($names);

print_r($names);

Output:

Array
(
    [0] => Anna
    [1] => Zack
    [2] => bob
    [3] => john
)

Uppercase letters are sorted before lowercase.

📌 Preserve Keys?

If you want to preserve keys while sorting, use asort() instead of sort().

$prices = [
    "apple" => 50,
    "banana" => 20,
    "mango" => 40
];
asort($prices);

print_r($prices);

Output:

Array
(
    [banana] => 20
    [mango] => 40
    [apple] => 50
)