PHP 5.6.0 released

bccomp

(PHP 4, PHP 5)

bccompCompara dos números de precisión arbitraria

Descripción

int bccomp ( string $left_operand = "" , string $right_operand = "" [, int $scale = int ] )

Compara el left_operand al right_operand y devuelve como resultado un entero.

Parámetros

left_operand

El left operand, como una cadena.

right_operand

El right operand, como una cadena.

scale

El parametro optativo scale es usado para indicar el número de dígitos decimales que se utilizarán en la comparación.

Valores devueltos

Devuelve 0 si los dos operandos son iguales, 1 si el left_operand es mayor que el right_operand, de lo contrario -1.

Ejemplos

Ejemplo #1 Ejemplobccomp()

<?php

echo bccomp('1''2') . "\n";   // -1
echo bccomp('1.00001''1'3); // 0
echo bccomp('1.00001''1'5); // 1

?>
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User Contributed Notes 6 notes

up
4
Robert Lozyniak
4 years ago
Beware that negative zero does not compare equal to positive zero.
up
2
Nitrogen
5 years ago
I made this to compare an unlimited size of numbers..

This could be useful for those without the BCMath extension.

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

<?php

function Comp($Num1,$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');

 
// remove leading zeroes from whole numbers
 
$Num1=ltrim($Tmp1[1],'0');
 
$Num2=ltrim($Tmp2[1],'0');

 
// first, we can just check the lengths of the numbers, this can help save processing time
  // if $Num1 is longer than $Num2, return 1.. vice versa with the next step.
 
if(strlen($Num1)>strlen($Num2)) return(1);
  else {
    if(
strlen($Num1)<strlen($Num2)) return(-1);

   
// if the two numbers are of equal length, we check digit-by-digit
   
else {

     
// 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'):'';

     
// if the user defined $Scale, then make sure we use that only
     
if($Scale!=null) {
       
$Dec1=substr($Dec1,0,$Scale);
       
$Dec2=substr($Dec2,0,$Scale);
      }

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

     
// append the padded decimals onto the end of the whole numbers
     
$Num1.=str_pad($Dec1,$DLen,'0');
     
$Num2.=str_pad($Dec2,$DLen,'0');

     
// check digit-by-digit, if they have a difference, return 1 or -1 (greater/lower than)
     
for($i=0;$i<strlen($Num1);$i++) {
        if((int)
$Num1{$i}>(int)$Num2{$i}) return(1);
        else
          if((int)
$Num1{$i}<(int)$Num2{$i}) return(-1);
      }

     
// if the two numbers have no difference (they're the same).. return 0
     
return(0);
    }
  }
}

$A="10.50002";
$B="10.50001";

printf("  Comp(%s,%s); // %s\r\n",$A,$BComp($A,$B));
printf("BCComp(%s,%s); // %s\r\n",$A,$B,BCComp($A,$B));

/*
    Comp(10.50002,10.50001); // 1
  BCComp(10.50002,10.50001); // 0 (BCComp has a default decimal scale of 0, unless specified)
*/

?>

I tried to make this behave like BCComp..

The only difference being mine will compare the decimals by default.. BCComp won't..
.. unless, of course, you specify the amount of decimals to include in the process.
Enjoy,
Nitrogen.
up
2
Anonymous
9 years ago
Note that the above function defeats the purpose of BCMath functions, for it uses the 'conventional' < operator.
Instead, it should be:
<?php
function my_bccomp_zero($amount, $scale)
{
   if (@
$amount{0}=="-")
   {
       return
bccomp($amount, '-0.0', $scale);
   }
   else
   {
       return
bccomp($amount, '0.0', $scale);
   }
}
?>
up
0
github.com/alixaxel/phunction/
2 years ago
You can wrap this function with version_compare() to have support for operators and friendlier (boolean) return values.

<?php

function _bccomp($a, $b, $operator = '=')
{
    return
version_compare(bccomp($a, $b), 0, $operator);
}

var_dump(_bccomp(5, 3, '>=')); // true

?>

Still works with arbitrary length numbers.
up
0
m dot kaczanowski at alianet dot pl
5 years ago
Improvement of functions bcmax() and bcmin() originaly written by frank at booksku dot com

<?php

function bcmax() {
 
$args = func_get_args();
  if (
count($args)==0) return false;
 
$max = $args[0];
  foreach(
$args as $value) {
    if (
bccomp($value, $max)==1) {
     
$max = $value;
    }
  }
  return
$max;
}

function
bcmin() {
 
$args = func_get_args();
  if (
count($args)==0) return false;
 
$min = $args[0];
  foreach(
$args as $value) {
    if (
bccomp($min, $value)==1) {
     
$min = $value;
    }
  }
  return
$min;
}
?>
up
0
frank at booksku dot com
8 years ago
I slapped together min() and max() functions using bccomp().  While min() and max() only take an arbitrary number of args (i.e. max(1, 5, 1235, 12934, 66)) bccomp only takes 2.

Note that this doesn't take into account $scale.

<?php

function bcmax() {
 
$max = null;
  foreach(
func_get_args() as $value) {
    if (
$max == null) {
     
$max = $value;
    } else if (
bccomp($max, $value) < 0) {
     
$max = $value;
    }
  }
  return
$max;
}

function
bcmin() {
 
$min = null;
  foreach(
func_get_args() as $value) {
    if (
$min == null) {
     
$min = $value;
    } else if (
bccomp($min, $value) > 0) {
     
$min = $value;
    }
  }
  return
$min;
}
?>
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