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bcdiv

(PHP 4, PHP 5, PHP 7)

bcdivDivide two arbitrary precision numbers

Description

bcdiv ( string $num1 , string $num2 [, int|null $scale = NULL ] ) : string

Divides the num1 by the num2.

Parameters

num1

The dividend, as a string.

num2

The divisor, as a string.

scale

This optional parameter is used to set the number of digits after the decimal place in the result. If omitted, it will default to the scale set globally with the bcscale() function, or fallback to 0 if this has not been set.

Return Values

Returns the result of the division as a string, or NULL if num2 is 0.

Changelog

Version Description
8.0.0 scale is now nullable.

Examples

Example #1 bcdiv() example

<?php

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

?>

See Also

  • bcmul() - Multiply two arbitrary precision numbers

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User Contributed Notes 4 notes

up
1
Anonymous
10 years ago
The custom bcdiv function listed at the top of this page produces very different results from bcdiv, as it rounds instead of truncating the result. Consider the following:

<?php

function bcdiv_cust( $first, $second, $scale = 0 )
{
   
$res = $first / $second;
    return
round( $res, $scale );
}

echo
bcdiv('1','2','0') . " vs. " bcdiv_cust('1','2','0');  // prints '0 vs. 1'

?>
up
0
MM
12 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;
up
-4
Gautam
13 years ago
<?php
//converting in to required precision of decimal points
$result= bcdiv(89.99999999997,2.57865741235478,2);
echo
"$result"// 34.90 result with 2 decimal points
?>
up
-7
cristianDOTzuddas]NOSPAM[gmailDOTcom
15 years ago
Decimal to binary conversion, using BC Math.
Note: this function is VERY slow if the decimal number is too big!

<?
function bc_decbin($dec_str) {
    if (strlen($dec_str)>0) {
        $bin_str = '';
        do {
            if (((int)$dec_str[strlen($dec_str)-1] % 2) === 0)
                $bin_str .= '0';
            else
                $bin_str .= '1';
           
            $dec_str = bcdiv($dec_str, '2');
        } while ($dec_str!='0');
       
        return strrev($bin_str);
    }
    else
        return null;
}
?>

-----
Cristian
www.CodeFlower.com
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