Unlock PHP 8’s New System Functions: fdiv, str_contains, mb_str_pad, bcceil & More

PHP System Functions Overview

PHP core provides built‑in functions for common tasks such as string manipulation, array handling, and mathematical operations. Since PHP 8.0 additional useful functions have been added.

1. fdiv()

<?php
// Floating‑point division, returns the quotient
echo fdiv(10, 3); // 3.333333333333
?>

2. str_contains()

<?php
$str = "125abc4556";
if (str_contains($str, 'abc')) {
    echo 'Found';
} else {
    echo 'Not Found';
}
?>

3. str_starts_with() and str_ends_with()

<?php
$str = "abc125abc4556xyz";
if (str_starts_with($str, 'abc')) {
    echo 'Starts with abc';
}
if (str_ends_with($str, 'xyz')) {
    echo 'Ends with xyz';
}
?>

4. Named arguments

<?php
function example(int $a, string $b): int|string {
    return $a . $b;
}
$m = example(a: 10, b: "hello");
var_dump($m); // string(7) "10hello"
?>

5. json_validate()

<?php
$res1 = json_validate('{ "test": { "foo": "bar" } }');
var_dump($res1); // bool(true)

$res2 = json_validate('{ "": "": "" }');
var_dump($res2); // bool(false)
?>

6. mb_str_pad()

<?php
// Pad a multibyte string to a given length (PHP 8.3+)
var_dump(mb_str_pad('▶▶', 6, '❤❓❇', STR_PAD_RIGHT)); // string(18) "▶▶❤❓❇❤"
var_dump(mb_str_pad('▶▶', 6, '❤❓❇', STR_PAD_LEFT));  // string(18) "❤❓❇❤▶▶"
var_dump(mb_str_pad('▶▶', 6, '❤❓❇', STR_PAD_BOTH));  // string(18) "❤❓▶▶❤❓"
var_dump(mb_str_pad('🎉', 3, '祝', STR_PAD_LEFT));    // string(10) "祝祝🎉"
?>

7. bcceil()

<?php
var_dump(bcceil('4.3'));   // string(1) "5"
var_dump(bcceil('9.999')); // string(1) "10"
var_dump(bcceil('-3.14'));// string(2) "-3"
?>

8. bcdivmod()

<?php
list($quot, $rem) = bcdivmod('5', '3');
echo $quot; // 1
echo $rem;  // 2

list($quot, $rem) = bcdivmod('-5', '3');
echo $quot; // -1
echo $rem;  // 2
?>

9. bcfloor()

<?php
var_dump(bcfloor('4.3'));   // string(1) "4"
var_dump(bcfloor('9.999')); // string(1) "9"
var_dump(bcfloor('-3.14'));// string(2) "-4"
?>

10. bcround()

<?php
var_dump(bcround('3.4'));               // "3"
var_dump(bcround('3.5'));               // "4"
var_dump(bcround('3.6'));               // "4"
var_dump(bcround('5.045', 2));          // "5.05"
var_dump(bcround('5.055', 2));          // "5.06"
var_dump(bcround('678', -2));           // "700"
var_dump(bcround('123.45', 3));         // "123.450"
var_dump(bcround('123.45', 2));         // "123.45"
var_dump(bcround('123.45', 1));         // "123.5"
var_dump(bcround('123', 0));             // "123"
var_dump(bcround('120', -1));           // "120"
var_dump(bcround('100', -2));           // "100"
var_dump(bcround('0', -3));            // "0"
?>

11. array_merge() new syntax

<?php
$arrayA = ['a' => 1];
$arrayB = ['b' => 2];
$result = array_merge(['c' => 0], $arrayA, $arrayB);
print_r($result); // Array ( [c] => 0 [a] => 1 [b] => 2 )
?>

12. array_is_list()

<?php
$array = [1, 2, 3];
var_dump(array_is_list($array)); // bool(true)

$array = ['a' => 1, 'b' => 2, 'c' => 3];
var_dump(array_is_list($array)); // bool(false)
?>

13. array_key_first(), array_key_last() and array_count_values()

<?php
$array = [1, 2, 3, 3];
echo array_key_first($array); // 0
echo array_key_last($array);  // 3
$ret = array_count_values($array);
print_r($ret); // Array ( [1] => 1 [2] => 1 [3] => 2 )
?>

14. password_hash() & password_verify()

<?php
$password = 'myLaravel';
$hash = password_hash($password, PASSWORD_DEFAULT); // Argon2id by default
$isValid = password_verify($password, $hash);
?>

15. array_find() and array_find_key()

<?php
$numbers = [1, 2, 3, 4];
$found = array_find($numbers, fn($v) => $v > 3); // 4

$users = [
    ['id' => 1, 'name' => 'Alice'],
    ['id' => 2, 'name' => 'Bob'],
];
$user = array_find_key($users, 'id', fn($k) => $k == 1);
print_r($user); // ['id'=>1,'name'=>'Alice']
?>