bcadd
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.
bccomp
(PHP 4, PHP 5)
bccomp — 2 つの任意精度数値を比較する
説明
int bccomp
( string
$left_operand
, string $right_operand
[, int $scale
] )
left_operand と
right_operand を比較し、
結果を整数値で返します。
パラメータ
-
left_operand -
左オペランドを表す文字列。
-
right_operand -
右オペランドを表す文字列。
-
scale -
オプションの
scaleパラメータで、 小数点以下の桁数を指定します。ここまでを使用して比較を行います。
返り値
ふたつのオペランドが等しければ 0、
left_operand が right_operand
より大きければ返り値は 1、小さければ -1 を返します。
例
例1 bccomp() の例
<?php
echo bccomp('1', '2') . "\n"; // -1
echo bccomp('1.00001', '1', 3); // 0
echo bccomp('1.00001', '1', 5); // 1
?>
add a note
User Contributed Notes
bccomp
github.com/alixaxel/phunction/
06-May-2012 07:19
Robert Lozyniak
16-Feb-2010 03:04
Beware that negative zero does not compare equal to positive zero.
Nitrogen
21-Jul-2009 12:23
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,$B, Comp($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.
m dot kaczanowski at alianet dot pl
11-Mar-2009 12:35
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;
}
?>
frank at booksku dot com
04-Oct-2005 09:41
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 $min;
}
?>
11-Feb-2005 07:03
Note that the above function defeats the purpose of BCMath functions, for it uses the 'conventional' < operator.
Instead, it should be:
<?php
function my_bccomp_zero($amount, $scale)
{
if (@$amount{0}=="-")
{
return bccomp($amount, '-0.0', $scale);
}
else
{
return bccomp($amount, '0.0', $scale);
}
}
?>