bcdiv

(PHP 4, PHP 5, PHP 7, PHP 8)

bcdiv — Divide two arbitrary precision numbers

Description

function bcdiv(string $num1, string $num2, ? int $scale = null ): string

Divides num1 by num2.

Parameters

num1: The dividend, as a string.
num2: The divisor, as a string.
scale: This parameter is used to set the number of digits after the decimal place in the result. If null , it will default to the default scale set with bcscale() , or fallback to the value of the bcmath.scale INI directive.

Return Values

Returns the result of the division as a string.

Errors/Exceptions

This function throws a ValueError in the following cases:

num1 or num2 is not a well-formed BCMath numeric string.
scale is outside the valid range.

This function throws a DivisionByZeroError exception if num2 is 0.

Changelog

Version	Description
8.0.0	`scale` is now nullable.
8.0.0	Dividing by `0` now throws a DivisionByZeroError exception instead of returning `null` .

Examples

Example #1 bcdiv() example

<?php

echo bcdiv('105', '6.55957', 3); // 16.007

?>

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User Contributed Notes 1 note

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MM ¶

18 years ago

Perhaps some one can find useful this function to compute the modular inverse of a integer (extended euclidean algorithm):
 function invmod($a,$b) {
 $n=$b;
 $x=0; $lx=1; $y=1; $ly=0;
 while ($b) {
 $t=$b;
 $q=bcdiv($a,$b,0);
 $b=bcmod($a,$b);
 $a=$t;
 $t=$x; $x=bcsub($lx,bcmod(bcmul($q,$x),$n)); $lx=$t;
 $t=$y; $y=bcsub($ly,bcmod(bcmul($q,$y),$n)); $ly=$t;
 }
 if (bccomp($lx,0) == -1)
 $lx=bcadd($lx,$n);
 return $lx;
 }
 // verify
 $n="2447995268898324993537772139997802321";
 $t="64941057316178801556773346239351236811";
 $m="123456789";
 $i=invmod($t,$n);
 // (t*m)*inv(t) is m
 echo bcmod(bcmul(bcmod(bcmul($t,$m),$n),$i),$n) == $m;