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    bcadd

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

    bcadd — Addition 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, $b, 4); // 6.2340

    ?>

    Siehe auch

    • bcsub() - Subtrahiert zwei Zahlen beliebiger Genauigkeit

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    User Contributed Notes 2 notes

    up
    27
    Nitrogen
    15 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",$A,$B,  Add($A,$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
    2
    Bo Anders Svensson
    19 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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