BC Math Functions
I made this to add an unlimited size of integers together (meaning no decimals)..
This could be useful for those without the BCMath extension.
<?php
function Add($Num1='0',$Num2='0') {
// check if they're both plain numbers
if(!preg_match("/^\d+$/",$Num1)||!preg_match("/^\d+$/",$Num2)) return(0);
// remove zeroes from beginning of numbers
for($i=0;$i<strlen($Num1);$i++) if(@$Num1{$i}!='0') {$Num1=substr($Num1,$i);break;}
for($i=0;$i<strlen($Num2);$i++) if(@$Num2{$i}!='0') {$Num2=substr($Num2,$i);break;}
// reverse both numbers and get their lengths
$Num1=strrev($Num1);$Len1=strlen($Num1);
$Num2=strrev($Num2);$Len2=strlen($Num2);
// calculate which is the longest in length
$MLen=max($Len1,$Len2);
// $Rema is for storing the calculated numbers (helps to carry the remainder)
$Rema=array();
// pad the numbers so they equal the same length (both equal to $MLen)
for($i=$Len1;$i<$MLen;$i++) $Num1.='0';
for($i=$Len2;$i<$MLen;$i++) $Num2.='0';
// cycle through each digit adding them together and add them to $Rema accordingly
for($i=0;$i<$MLen;$i++) $Rema[$i]=(string)((int)$Num1{$i})+((int)$Num2{$i});
// cycle through $Rema and if the item contains 2 digits, then carry the first
// digit to the next item in $Rema
for($i=0;$i<count($Rema);$i++) {
$Rema2=str_split($Rema[$i]);
if(count($Rema2)>=2) {
$Rema[$i]=$Rema2[1];
@$Rema[$i+1]+=$Rema2[0];
}
}
// implode $Rema so it's a string and reverse it, this is the result!
return(strrev(implode($Rema)));
}
$A='5650175242508133742';
$B='2361030539975818701734615584174625';
printf(" Add(%s,%s); // %s\r\n",$A,$B, Add($A,$B));
printf("BCAdd(%s,%s); // %s\r\n",$A,$B,BCAdd($A,$B)); // build-in function
/*
This will print something similar to this..
Add(5650175242508133742,2361030539975818701734615584174625);
BCAdd(5650175242508133742,2361030539975818701734615584174625);
both of which should be followed by the answer:
2361030539975824351909858092308367
*/
?>
It was a fun experience making, and thought I'd share it.
Enjoy,
Nitrogen.
bcadd
(PHP 4, PHP 5)
bcadd — Add two arbitrary precision numbers
Description
string bcadd
( string $left_operand
, string $right_operand
[, int $scale
] )
Sums left_operand and right_operand .
Parameters
- left_operand
-
The left operand, as a string.
- right_operand
-
The right operand, as a string.
- scale
-
This optional parameter is used to set the number of digits after the decimal place in the result. You can also set the global default scale for all functions by using bcscale().
Return Values
The sum of the two operands, as a string.
Examples
Example #1 bcadd() example
<?php
$a = '1.234';
$b = '5';
echo bcadd($a, $b); // 6
echo bcadd($a, $b, 4); // 6.2340
?>
add a note
User Contributed Notesbcadd
Nitrogen
30-Jun-2009 08:53
30-Jun-2009 08:53
Bo Anders Svensson
23-May-2005 12:25
23-May-2005 12:25
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