PHP: intdiv - Manual (original) (raw)

(PHP 7, PHP 8)

intdiv — Integer division

Description

Parameters

num1

Number to be divided.

num2

Number which divides the num1.

Return Values

The integer quotient of the division of num1 by num2.

Examples

Example #1 intdiv() example

<?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)); ?>

The above example will output:

int(1) int(-1) int(-1) int(1) int(1) int(1)

Example #2 intdiv() Example With Invalid Divisor

`<?php
try {
intdiv(PHP_INT_MIN, -1);
} catch (Error $e) {
echo get_class($e), ': ', $e->getMessage(), PHP_EOL;
}

try {

intdiv(1, 0);
} catch (Error $e) {
echo get_class($e), ': ', $e->getMessage(), PHP_EOL;
}
?>`

The above example will output:

ArithmeticError: Division of PHP_INT_MIN by -1 is not an integer DivisionByZeroError: Division by zero

See Also

/ - Floating-point division
% - Integer modulus
fmod() - Returns the floating point remainder (modulo) of the division of the arguments - Floating-point modulo

Found A Problem?

AmeenRoss ¶

10 years ago

This does indeed seem to be equal to intdiv:

<?php
function intdiv_1($a, $b){
    return ($a - <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>a</mi></mrow><annotation encoding="application/x-tex">a % </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">a</span></span></span></span>b) / $b;
}
?>

However, this isn't:

<?php
function 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
 * )
 */
?>

oittaa ¶

3 years ago

Python style integer division, where the result is always rounded towards minus infinity.

1 // 2 is 0
(-1) // 2 is -1
1 // (-2) is -1
(-1) // (-2) is 0

<?php
function intdiv_py(int <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mn>1</mn><mo separator="true">,</mo><mi>i</mi><mi>n</mi><mi>t</mi></mrow><annotation encoding="application/x-tex">num1, int </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.854em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">m</span><span class="mord">1</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">in</span><span class="mord mathnormal">t</span></span></span></span>num2): int{
    if ($num1 < 0 xor $num2 < 0){
        <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mn>1</mn><mo>=</mo><mi>a</mi><mi>b</mi><mi>s</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">num1 = abs(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">m</span><span class="mord">1</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">ab</span><span class="mord mathnormal">s</span><span class="mopen">(</span></span></span></span>num1);
        <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mn>2</mn><mo>=</mo><mi>a</mi><mi>b</mi><mi>s</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">num2 = abs(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">m</span><span class="mord">2</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">ab</span><span class="mord mathnormal">s</span><span class="mopen">(</span></span></span></span>num2);
        <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>r</mi><mi>e</mi><mi>m</mi><mi>a</mi><mi>i</mi><mi>n</mi><mi>d</mi><mi>e</mi><mi>r</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">remainder = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">re</span><span class="mord mathnormal">main</span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>num1 % $num2;
        return <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>r</mi><mi>e</mi><mi>m</mi><mi>a</mi><mi>i</mi><mi>n</mi><mi>d</mi><mi>e</mi><mi>r</mi><mo stretchy="false">?</mo><mo>−</mo><mn>1</mn><mo>−</mo><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">remainder ? -1 -(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.7778em;vertical-align:-0.0833em;"></span><span class="mord mathnormal">re</span><span class="mord mathnormal">main</span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mclose">?</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord">1</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">−</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mopen">(</span></span></span></span>num1 - <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>r</mi><mi>e</mi><mi>m</mi><mi>a</mi><mi>i</mi><mi>n</mi><mi>d</mi><mi>e</mi><mi>r</mi><mo stretchy="false">)</mo><mi mathvariant="normal">/</mi></mrow><annotation encoding="application/x-tex">remainder) / </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">re</span><span class="mord mathnormal">main</span><span class="mord mathnormal">d</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mclose">)</span><span class="mord">/</span></span></span></span>num2 : -$num1 / $num2;
    }
    return intdiv($num1, $num2);
}

var_dump(intdiv_py(1, 2)); // 0
var_dump(intdiv_py(-1, 2)); // -1
var_dump(intdiv_py(1, -2)); // -1
var_dump(intdiv_py(-1, -2)); // 0
?>