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bcadd

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

bcaddAddition zweier Zahlen beliebiger Genauigkeit

Beschreibung

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

Addiert den num1 (linken Operanden) zum num2 (rechten Operanden).

Parameter-Liste

num1

Der linke Operand in Stringform.

num2

Der rechte Operand in Stringform.

scale

Dieser optionale Parameter kann benutzt werden, um die Anzahl der Nachkommastellen im Ergebnis festzulegen. Sie können mit Hilfe der bcscale()-Funktion auch einen globalen Vorgabewert für alle Funktionen festlegen.

Rückgabewerte

Die Summe beider Operanden in Stringform.

Changelog

Version Beschreibung
8.0.0 scale ist jetzt nullbar.

Beispiele

Beispiel #1 bcadd()-Beispiel

<?php

$a 
'1.234';
$b '5';

echo 
bcadd($a$b);     // 6
echo bcadd($a$b4);  // 6.2340

?>

Siehe auch

  • bcsub() - Subtrahiert zwei Zahlen beliebiger Genauigkeit

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User Contributed Notes 2 notes

up
23
Nitrogen
12 years ago
I made this to add an unlimited size of numbers together..

This could be useful for those without the BCMath extension.

It allows decimals, and optional $Scale parameter.  If $Scale isn't specified, then it'll automatically adjust to show the correct number of decimals.

<?php

function Add($Num1,$Num2,$Scale=null) {
 
// check if they're valid positive numbers, extract the whole numbers and decimals
 
if(!preg_match("/^\+?(\d+)(\.\d+)?$/",$Num1,$Tmp1)||
     !
preg_match("/^\+?(\d+)(\.\d+)?$/",$Num2,$Tmp2)) return('0');

 
// this is where the result is stored
 
$Output=array();

 
// remove ending zeroes from decimals and remove point
 
$Dec1=isset($Tmp1[2])?rtrim(substr($Tmp1[2],1),'0'):'';
 
$Dec2=isset($Tmp2[2])?rtrim(substr($Tmp2[2],1),'0'):'';

 
// calculate the longest length of decimals
 
$DLen=max(strlen($Dec1),strlen($Dec2));

 
// if $Scale is null, automatically set it to the amount of decimal places for accuracy
 
if($Scale==null) $Scale=$DLen;

 
// remove leading zeroes and reverse the whole numbers, then append padded decimals on the end
 
$Num1=strrev(ltrim($Tmp1[1],'0').str_pad($Dec1,$DLen,'0'));
 
$Num2=strrev(ltrim($Tmp2[1],'0').str_pad($Dec2,$DLen,'0'));

 
// calculate the longest length we need to process
 
$MLen=max(strlen($Num1),strlen($Num2));

 
// pad the two numbers so they are of equal length (both equal to $MLen)
 
$Num1=str_pad($Num1,$MLen,'0');
 
$Num2=str_pad($Num2,$MLen,'0');

 
// process each digit, keep the ones, carry the tens (remainders)
 
for($i=0;$i<$MLen;$i++) {
   
$Sum=((int)$Num1{$i}+(int)$Num2{$i});
    if(isset(
$Output[$i])) $Sum+=$Output[$i];
   
$Output[$i]=$Sum%10;
    if(
$Sum>9) $Output[$i+1]=1;
  }

 
// convert the array to string and reverse it
 
$Output=strrev(implode($Output));

 
// substring the decimal digits from the result, pad if necessary (if $Scale > amount of actual decimals)
  // next, since actual zero values can cause a problem with the substring values, if so, just simply give '0'
  // next, append the decimal value, if $Scale is defined, and return result
 
$Decimal=str_pad(substr($Output,-$DLen,$Scale),$Scale,'0');
 
$Output=(($MLen-$DLen<1)?'0':substr($Output,0,-$DLen));
 
$Output.=(($Scale>0)?".{$Decimal}":'');
  return(
$Output);
}

$A="5650175242.508133742";
$B="308437806.831153821478770";

printf("  Add(%s,%s);\r\n// %s\r\n\r\n",$A,$BAdd($A,$B));
printf("BCAdd(%s,%s);\r\n// %s\r\n\r\n",$A,$B,BCAdd($A,$B));

/*
  This will produce the following..
    Add(5650175242.508133742,308437806.831153821478770);
  // 5958613049.33928756347877

  BCAdd(5650175242.508133742,308437806.831153821478770);
  // 5958613049
*/

?>

It was a fun experience making, and thought I'd share it.
Enjoy,
Nitrogen.
up
5
Bo Anders Svensson
16 years ago
Be aware:

$exp1 = "1E5";
$exp2 = "2E4";

$ans1 = bcadd((float)$exp1, (float)$exp2, 3);
$ans2 = bcadd((int)$exp1, (int)$exp2, 3);
$ans3 = bcadd($exp1, $exp2, 3);

echo "1: $exp1 + $exp2 = $ans1\r\n";
echo "2: $exp1 + $exp2 = $ans2\r\n";
echo "3: $exp1 + $exp2 = $ans3\r\n";

1: 1E5 + 2E4 = 120000.000
2: 1E5 + 2E4 = 3.000
3: 1E5 + 2E4 = 0.000
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