intdiv

    (PHP 7, PHP 8)

    intdiv — 整数値の除算

    説明

    intdiv(int $num1, int $num2): int

    num1 を num2 で割った整数商を返します。

    パラメータ

    num1

    割られる数。

    num2

    num1 を割る数。

    戻り値

    num1 を num2 で割った整数商。

    エラー / 例外

    num2 が 0 の場合、DivisionByZeroError 例外がスローされます。num1 が PHP_INT_MIN で num2 が -1 の場合、 ArithmeticError 例外がスローされます。

    例

    例1 intdiv() の例

    <?php
    var_dump    (intdiv(3, 2));
    var_dump(intdiv(-3, 2));
    var_dump(intdiv(3, -2));
    var_dump(intdiv(-3, -2));
    var_dump(intdiv(PHP_INT_MAX, PHP_INT_MAX));
    var_dump(intdiv(PHP_INT_MIN, PHP_INT_MIN));
    var_dump(intdiv(PHP_INT_MIN, -1));
    var_dump(intdiv(1, 0));
    ?>
    int(1)
int(-1)
int(-1)
int(1)
int(1)
int(1)

Fatal error: Uncaught ArithmeticError: Division of PHP_INT_MIN by -1 is not an integer in %s on line 8
Fatal error: Uncaught DivisionByZeroError: Division by zero in %s on line 9

    参考

    • / - 浮動小数点数値の除算
    • % - 整数値の剰余
    • fmod() - 引数で除算をした際の剰余を返す - 浮動小数点数値の剰余

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    User Contributed Notes 2 notes

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    42
    AmeenRoss
    10 years ago
    This does indeed seem to be equal to intdiv:<?phpfunction intdiv_1($a, $b){    return ($a - $a % $b) / $b;}?>However, this isn't:<?phpfunction intdiv_2($a, $b){    return floor($a / $b);}?>Consider an example where either of the parameters is negative:<?php$param1 = -10;$param2 = 3;print_r([    'modulus' => intdiv_1($param1, $param2),    'floor' => intdiv_2($param1, $param2),]);/** * Array * ( *     [modulus] => -3 *     [floor] => -4 * ) */?>
    up
    5
    oittaa
    3 years ago
    Python style integer division, where the result is always rounded towards minus infinity.1 // 2 is 0(-1) // 2 is -11 // (-2) is -1(-1) // (-2) is 0<?phpfunction intdiv_py(int $num1, int $num2): int{    if ($num1 < 0 xor $num2 < 0){        $num1 = abs($num1);        $num2 = abs($num2);        $remainder = $num1 % $num2;        return $remainder ? -1 -($num1 - $remainder) / $num2 : -$num1 / $num2;    }    return intdiv($num1, $num2);}var_dump(intdiv_py(1, 2)); // 0var_dump(intdiv_py(-1, 2)); // -1var_dump(intdiv_py(1, -2)); // -1var_dump(intdiv_py(-1, -2)); // 0?>
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