clamp

(PHP 8 >= 8.6.0)

clamp — Return the given value if in range, else return the nearest bound

説明

function clamp(mixed $value, mixed $min, mixed $max): mixed

Return the given value if in range of min and max. Else if it's lower than min, return min. Else return max.

注意:
Values of different types will be compared using the standard comparison rules. For instance, a non-numeric string will be compared to an int as though it were 0, but multiple non-numeric string values will be compared alphanumerically. The actual value returned will be of the original type with no conversion applied.

警告

Be careful when passing arguments of different types because clamp() can produce unpredictable results.

パラメータ

value: Any comparable value to be clamped between min and max.
min: A comparable minimum to limit the value to.
max: A comparable maximum to limit the value to.

戻り値

clamp() returns the parameter value if considered "between" min and max according to standard comparisons.

If value is NAN, then the returned value will also be NAN.

エラー / 例外

If min is greater than max, clamp() throws a ValueError.

If min or max is NAN, clamp() throws a ValueError.

例

<?php
echo clamp(-5, min: 0, max: 100), PHP_EOL;  // 0
echo clamp(55, min: 0, max: 100), PHP_EOL;  // 55
echo clamp(103, min: 0, max: 100), PHP_EOL;  // 100

echo clamp("J", min: "A", max: "F"), PHP_EOL;  // "F"

clamp(
    new \DateTimeImmutable('2025-08-01'),
    min: new \DateTimeImmutable('2025-08-15'),
    max: new \DateTimeImmutable('2025-09-15'),
)->format('Y-m-d'), PHP_EOL; // 2025-08-15
?>

参考

min() - 最小値を返す
max() - 最大値を返す

関連キーワード:

clamp return Return given range mixed else nearest bound compared comparable DateTimeImmutable Else different types standard numeric returned between limit throws ValueError ceil Math lower