PHP - Manual: intdiv

2024-11-15

is_finite »

« hypot

intdiv

(PHP 7, PHP 8)

intdiv — 对除法结果取整

说明

intdiv(int $dividend, int $divisor): int

返回 dividend 除以 divisor 商数的整数部分。

参数

dividend: 被除数。
divisor: 除数。

返回值

dividend 除以 divisor 的商，对该商取整。

错误／异常

如果 divisor 是 0，将抛出 DivisionByZeroError 异常。如果 dividend 是 PHP_INT_MIN 并且 divisor 是 -1，将抛出 ArithmeticError 异常.

范例

示例 #1 intdiv() 的一些例子


<?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

add a note

User Contributed Notes 7 notes

down

AmeenRoss ¶

6 years ago


This does indeed seem to be equal to intdiv:

<?php
function intdiv_1($a, $b){
    return ($a - $a % $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
 * )
 */
?>

down

sree dot millu at gmail dot com ¶

2 years ago


@AmeenRoss 
This does NOT  seem to be equal to intdiv:

<?php
function intdiv_1($a, $b){
    return ($a - $a % $b) / $b;
}
?>

See this example code
<?php 

$x = 5.6;
$y = 1.4 ;

echo intdiv($x,$y);
    
    echo "\n";
    
function intdiv_1($a, $b){
    return ($a - $a % $b) / $b;
}    

echo intdiv_1($x,$y);
?>

//Output
5
4

down

oittaa ¶

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

down

-19

polettog at gmail dot com ¶

6 years ago


Without intdiv(), the following may be a good way (with $a and $b of type integer and not too big) :
<?php
(int)($a / $b)
?>
because in case of divisible integers, the result will be integer and there is no risk of float appearing round but below their represented value (like the case (0.1+0.7)*10).
$a and $b really needs to be of type integer though. 
If they are too big and indivisible, some precision will be lost during the conversion to float and the result may be inaccurate.

down

-26

Ts.Saltan ¶

7 years ago


$a = 57;
$b = 3;

var_dump(
    intdiv($a,$b),
    intdiv_1($a,$b),
    intdiv_2($a,$b)
);

function intdiv_1($a, $b){
    return ($a-$a%$b)/$b;
}

function intdiv_2($a, $b){
    return floor($a/$b);
}
//intdiv($a, $b) == floor($a/$b) == ($a-$a%$b)/$b

down

-10

admin at infis dot net dot ru ¶

2 years ago


For earler versions PHP you may use:

function intdiv_1($a, $b) {
    $a = (int) $a;
    $b = (int) $b;
    return ($a - fmod($a, $b)) / $b;
}

down

-35

Bubonic dot pestilence at gmail dot com ¶

6 years ago


<?php

function intdiv_2($a, $b)  {
    $val = $a / $b;
    return ($val < 0 ? "ceil" : "floor") ($val);
} 

?>

Aren't this?!

add a note

官方地址：https://www.php.net/manual/en/function.intdiv.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL 数据库面试 C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet ADORecordSet对象 adodb手册 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 opcache预加载 Composer的Packagist资源 mysql面试题 [鸟哥]PHP FFI详解 - 一种全新的PHP扩展方式 PHP7添加redis扩展 PHP mkdir()写出来的权限与mode值不符合 Packagist / Composer 中国全量镜像支持php7的性能采集扩展 adodb连接mysql多个数据库的问题 php $_SERVER中的SERVER_NAME 和HTTP_HOST的区别

略微加速

PHP官方手册 - 互联网笔记

intdiv

说明

参数

返回值

错误／异常

范例

User Contributed Notes 7 notes