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bcdiv

(PHP 4, PHP 5, PHP 7)

bcdivDivide two arbitrary precision numbers

Descrierea

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

Divides the num1 by the num2.

Parametri

num1

The dividend, as a string.

num2

The divisor, as a string.

scale

Acest parametru opțional este utilizat pentru a stabili numărul cifrelor după virgulă din rezultat. Dacă este omis, valoarea implicită va fi cea stabilită global cu funcția bcscale(), sau va fi 0 dacă nu a fost stabilită cu ajutorul acestei funcții.

Valorile întoarse

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

Istoricul schimbărilor

Versiune Descriere
8.0.0 scale is now nullable.

Exemple

Example #1 bcdiv() example

<?php

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

?>

A se vedea și

  • bcmul() - Multiply two arbitrary precision numbers

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User Contributed Notes 4 notes

up
0
Anonymous
11 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
-1
MM
13 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
-6
Gautam
14 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
-8
cristianDOTzuddas]NOSPAM[gmailDOTcom
16 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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