base_convert

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

base_convertWandelt einen numerischen Wert zwischen verschiedenen Zahlensystemen um

Beschreibung

base_convert(string $num, int $from_base, int $to_base): string

base_convert() gibt eine Zeichenkette zurück, die num in der Darstellung des Zahlensystems to_base enthält. Das Zahlensystem, in dem die Zahl num vorliegt, wird in from_base angegeben. Sowohl from_base als auch to_base müssen zwischen 2 und 36 (inklusive) liegen. In Zahlensystemen mit einer Basis größer als zehn werden die Zahlen größer als neun durch die Buchstaben a bis z dargestellt. Dabei steht a für 10, b für 11 und so weiter bis z für 35. Die Groß- und Kleinschreibung der Buchstaben spielt dabei keine Rolle, d.h. num wird ohne Berücksichtigung der Groß- und Kleinschreibung ausgewertet.

Warnung

base_convert() kann bei großen Werten auf Grund von Eigenschaften des zugrunde liegenden internen Datentyps float die Genauigkeit verschlechtern. Nähere Informationen hierzu und zu den Einschränkungen sind im Abschnitt Gleitkommazahlen des Handbuchs zu finden.

Parameter-Liste

num

Die umzuwandelnde numerische Zeichenkette. Alle ungültigen Zeichen werden ohne Warnung ignoriert. Von PHP 7.4.0 an ist die Übergabe jeglicher ungültiger Zeichen missbilligt.

from_base

Die Basis, zu der num kodiert ist

to_base

Die Basis, zu der num umgewandelt werden soll

Rückgabewerte

num umgewandelt zur Basis to_base.

Changelog

Version Beschreibung
7.4.0 Die Übergabe ungültiger Zeichen löst nun einen Hinweis aus, dass dies veraltet ist. Das Ergebnis wird weiterhin so berechnet, als würden die ungültigen Zeichen nicht existieren.

Beispiele

Beispiel #1 base_convert()-Beispiel

<?php
$hexadecimal
= 'a37334';
echo
base_convert($hexadecimal, 16, 2);
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

101000110111001100110100

Siehe auch

  • intval() - Konvertiert einen Wert nach integer

add a note add a note

User Contributed Notes 24 notes

up
81
PHPCoder at niconet2k dot com
12 years ago
Convert an arbitrarily large number from any base to any base.

string convBase(string $numberInput, string $fromBaseInput, string $toBaseInput)
$numberInput number to convert as a string
$fromBaseInput base of the number to convert as a string
$toBaseInput base the number should be converted to as a string
examples for $fromBaseInput and $toBaseInput
'0123456789ABCDEF' for Hexadecimal (Base16)
'0123456789' for Decimal (Base10)
'01234567' for Octal (Base8)
'01' for Binary (Base2)
You can really put in whatever you want and the first character is the 0.
Examples:

<?php
convBase
('123', '0123456789', '01234567');
//Convert '123' from decimal (base10) to octal (base8).
//result: 173

convBase('70B1D707EAC2EDF4C6389F440C7294B51FFF57BB', '0123456789ABCDEF', '01');
//Convert '70B1D707EAC2EDF4C6389F440C7294B51FFF57BB' from hexadecimal (base16) to binary (base2).
//result:
//111000010110001110101110000011111101010110000101110
//110111110100110001100011100010011111010001000000110
//001110010100101001011010100011111111111110101011110
//111011

convBase('1324523453243154324542341524315432113200203012', '012345', '0123456789ABCDEF');
//Convert '1324523453243154324542341524315432113200203012' from senary (base6) to hexadecimal (base16).
//result: 1F9881BAD10454A8C23A838EF00F50

convBase('355927353784509896715106760','0123456789','Christopher');
//Convert '355927353784509896715106760' from decimal (base10) to undecimal (base11) using "Christopher" as the numbers.
//result: iihtspiphoeCrCeshhorsrrtrh

convBase('1C238Ab97132aAC84B72','0123456789aAbBcCdD', '~!@#$%^&*()');
//Convert'1C238Ab97132aAC84B72' from octodecimal (base18) using '0123456789aAbBcCdD' as the numbers to undecimal (base11) using '~!@#$%^&*()' as the numbers.
//result: !%~!!*&!~^!!&(&!~^@#@@@&

function convBase($numberInput, $fromBaseInput, $toBaseInput)
{
    if (
$fromBaseInput==$toBaseInput) return $numberInput;
   
$fromBase = str_split($fromBaseInput,1);
   
$toBase = str_split($toBaseInput,1);
   
$number = str_split($numberInput,1);
   
$fromLen=strlen($fromBaseInput);
   
$toLen=strlen($toBaseInput);
   
$numberLen=strlen($numberInput);
   
$retval='';
    if (
$toBaseInput == '0123456789')
    {
       
$retval=0;
        for (
$i = 1;$i <= $numberLen; $i++)
           
$retval = bcadd($retval, bcmul(array_search($number[$i-1], $fromBase),bcpow($fromLen,$numberLen-$i)));
        return
$retval;
    }
    if (
$fromBaseInput != '0123456789')
       
$base10=convBase($numberInput, $fromBaseInput, '0123456789');
    else
       
$base10 = $numberInput;
    if (
$base10<strlen($toBaseInput))
        return
$toBase[$base10];
    while(
$base10 != '0')
    {
       
$retval = $toBase[bcmod($base10,$toLen)].$retval;
       
$base10 = bcdiv($base10,$toLen,0);
    }
    return
$retval;
}
?>
up
35
JR
12 years ago
Short arabic2roman conveter:

<?php
function rome($N){
       
$c='IVXLCDM';
        for(
$a=5,$b=$s='';$N;$b++,$a^=7)
                for(
$o=$N%$a,$N=$N/$a^0;$o--;$s=$c[$o>2?$b+$N-($N&=-2)+$o=1:$b].$s);
        return
$s;
}
?>

And it works :)
up
24
Clifford dot ct at gmail dot com
11 years ago
If you use base_convert to convert a large (eg. 80-bit) hexadecimal to base-36, you might observe:

ABCDEF00001234567890 (hexadecimal) => 3O47RE02JZSW0KS8 (base-36) => ABCDEF00001240000000 (hexadecimal)

This is normal and is due to the loss of precision on large numbers.

I have written a string-based function using the built-in BC Math Extension which will overcome this and similar problems.

<?php

function str_baseconvert($str, $frombase=10, $tobase=36) {
   
$str = trim($str);
    if (
intval($frombase) != 10) {
       
$len = strlen($str);
       
$q = 0;
        for (
$i=0; $i<$len; $i++) {
           
$r = base_convert($str[$i], $frombase, 10);
           
$q = bcadd(bcmul($q, $frombase), $r);
        }
    }
    else
$q = $str;

    if (
intval($tobase) != 10) {
       
$s = '';
        while (
bccomp($q, '0', 0) > 0) {
           
$r = intval(bcmod($q, $tobase));
           
$s = base_convert($r, 10, $tobase) . $s;
           
$q = bcdiv($q, $tobase, 0);
        }
    }
    else
$s = $q;

    return
$s;
}

?>

Typical use-cases:
1.  Convert a large arbitrary precision number to base-36.
2.  Convert a 32-char hexadecimal UUID (128-bit) to a 25-char base-36 unique key, and vice versa.

Examples:

<?php
$b16
= 'ABCDEF00001234567890';
$b36 = str_baseconvert($b16, 16, 36);
echo (
"$b16 (hexadecimal) = $b36 (base-36) \\n");

$uuid = 'ABCDEF01234567890123456789ABCDEF';
$ukey = str_baseconvert($uuid, 16, 36);
echo (
"$uuid (hexadecimal) = $ukey (base-36) \\n");
?>

ABCDEF00001234567890 (hexadecimal) = 3o47re02jzqisvio (base-36)
ABCDEF01234567890123456789ABCDEF (hexadecimal) = a65xa07491kf5zyfpvbo76g33 (base-36)
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3
Anonymous
6 years ago
some other mini implementation of base32 without error catching. just bring things from 5 to 8 and 8 to 5 bit. greetings. mho

<?
function base32_decode($d)
    {
    list($t, $b, $r) = array("ABCDEFGHIJKLMNOPQRSTUVWXYZ234567", "", "");

    foreach(str_split($d) as $c)
        $b = $b . sprintf("%05b", strpos($t, $c));

    foreach(str_split($b, 8) as $c)
        $r = $r . chr(bindec($c));

    return($r);
    }

function base32_encode($d)
    {
    list($t, $b, $r) = array("ABCDEFGHIJKLMNOPQRSTUVWXYZ234567", "", "");

    foreach(str_split($d) as $c)
        $b = $b . sprintf("%08b", ord($c));

    foreach(str_split($b, 5) as $c)
        $r = $r . $t[bindec($c)];

    return($r);
    }
?>
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11
lindsay at bitleap dot com
19 years ago
If you need to use base_convert with numbers larger then 32 bit, the following gmp implementation of base_convert should work.

<?php

/*use gmp library to convert base. gmp will convert numbers > 32bit*/
function gmp_convert($num, $base_a, $base_b)
{
        return
gmp_strval ( gmp_init($num, $base_a), $base_b );
}

?>
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11
Theriault
14 years ago
If you would like to convert numbers into just the uppercase alphabet base and vice-versa (e.g. the column names in a Microsoft Windows Excel sheet..A-Z, AA-ZZ, AAA-ZZZ, ...), the following functions will do this.

<?php

/**
* Converts an integer into the alphabet base (A-Z).
*
* @param int $n This is the number to convert.
* @return string The converted number.
* @author Theriault
*
*/
function num2alpha($n) {
   
$r = '';
    for (
$i = 1; $n >= 0 && $i < 10; $i++) {
       
$r = chr(0x41 + ($n % pow(26, $i) / pow(26, $i - 1))) . $r;
       
$n -= pow(26, $i);
    }
    return
$r;
}
/**
* Converts an alphabetic string into an integer.
*
* @param int $n This is the number to convert.
* @return string The converted number.
* @author Theriault
*
*/
function alpha2num($a) {
   
$r = 0;
   
$l = strlen($a);
    for (
$i = 0; $i < $l; $i++) {
       
$r += pow(26, $i) * (ord($a[$l - $i - 1]) - 0x40);
    }
    return
$r - 1;
}

?>

Microsoft Windows Excel stops at IV (255), but this function can handle much larger. However, English words will start to form after a while and some may be offensive, so be careful.
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3
AdamJacobMuller at AdamJacobMuller dot com
19 years ago
<?php
function binarycodedstring2dec($binary) {
       
$len=strlen($binary);
       
$rows=($len/4)-1;
        if ((
$len%4)>0) {
               
$pad=$len+(4-($len%4));
               
$binary=str_pad($binary,$pad,"0",STR_PAD_LEFT);
               
$len=strlen($binary);
               
$rows=($len/4)-1;
        }
       
$x=0;
        for (
$x=0;$x<=$rows;$x++) {
               
$s=($x*4);
               
$bins=$binary[$s].$binary[$s+1].$binary[$s+2].$binary[$s+3];
               
$num=base_convert($bins,2,10);
                if (
$num>9) {
                        die(
"the string is not a proper binary coded decimal\n");
                } else {
                       
$res.=$num;
                }
        }
        return
$res;
}
?>

a binary coded decimal is converted by taking groups of four from a decimal string,
for example the binary coded decimal string
1000 = 8
10001000 does not = 136 but 88
so
binarycodedstring2dec(1000) = 8
binarycodedstring2dec(11100000111001)=3839
binarycodedstring2dec(100000111001)=839

i truly have no idea if this function will be useful to anyone, i simply failed a physics midterm because i didn't know this so i wrote this function to make sure i would never forget how to convert binary coded decimals
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1
andrew at youritland dot co dot uk
9 years ago
Example of using base_convert to generate random passwords

function random_password()
{
  $rvalue1 = mt_rand(100,999);
  $rvalue2 = time();
  $rvalue3 = mt_rand(1000,9999);
  $rvalue4 = mt_rand(1,9);
  $rvalue5 = mt_rand(101,109);
  //combine values
  $rvalues = intval(((($rvalue2.$rvalue3) + $rvalue1)*$rvalue4) / $rvalue5);
 
  //return value in base-35 (will contain chars from '0' to 'z')
  return base_convert($rvalues,10,35);
}

Change the range of rvalue5 to get more or less characters. This setting
will return 8 chars.
up
2
cyrilbele at yahoo dot fr
14 years ago
If you want to do sharding, at some point you will need to decide which shard to target. Here is a simple function to assign the data to a particular shard based on a key (usually identifier of the row)

Here is a simple function to get the shard based on the key and the number of shards available

<?php
function getShard($key,$nbShards) {
   
$num = substr(base_convert(sha1($key), 16, 10),4,6);
    return
$num%$nbShards;
}
?>
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4
bryan at bryanruiz dot com
13 years ago
A RFC 4648 Compliant Base32 encode.  Send me an email if you end up making this thing more efficient with bitwise operations and whatever else.

<?php

/**
* Encode in Base32 based on RFC 4648.
* Requires 20% more space than base64 
* Great for case-insensitive filesystems like Windows and URL's  (except for = char which can be excluded using the pad option for urls)
*
* @package default
* @author Bryan Ruiz
**/
class Base32 {

   private static
$map = array(
       
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', //  7
       
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 15
       
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 23
       
'Y', 'Z', '2', '3', '4', '5', '6', '7', // 31
       
'='  // padding char
   
);
   
   private static
$flippedMap = array(
       
'A'=>'0', 'B'=>'1', 'C'=>'2', 'D'=>'3', 'E'=>'4', 'F'=>'5', 'G'=>'6', 'H'=>'7',
       
'I'=>'8', 'J'=>'9', 'K'=>'10', 'L'=>'11', 'M'=>'12', 'N'=>'13', 'O'=>'14', 'P'=>'15',
       
'Q'=>'16', 'R'=>'17', 'S'=>'18', 'T'=>'19', 'U'=>'20', 'V'=>'21', 'W'=>'22', 'X'=>'23',
       
'Y'=>'24', 'Z'=>'25', '2'=>'26', '3'=>'27', '4'=>'28', '5'=>'29', '6'=>'30', '7'=>'31'
   
);
   
   
/**
     *    Use padding false when encoding for urls
     *
     * @return base32 encoded string
     * @author Bryan Ruiz
     **/
   
public static function encode($input, $padding = true) {
        if(empty(
$input)) return "";
       
$input = str_split($input);
       
$binaryString = "";
        for(
$i = 0; $i < count($input); $i++) {
           
$binaryString .= str_pad(base_convert(ord($input[$i]), 10, 2), 8, '0', STR_PAD_LEFT);
        }
       
$fiveBitBinaryArray = str_split($binaryString, 5);
       
$base32 = "";
       
$i=0;
        while(
$i < count($fiveBitBinaryArray)) {   
           
$base32 .= self::$map[base_convert(str_pad($fiveBitBinaryArray[$i], 5,'0'), 2, 10)];
           
$i++;
        }
        if(
$padding && ($x = strlen($binaryString) % 40) != 0) {
            if(
$x == 8) $base32 .= str_repeat(self::$map[32], 6);
            else if(
$x == 16) $base32 .= str_repeat(self::$map[32], 4);
            else if(
$x == 24) $base32 .= str_repeat(self::$map[32], 3);
            else if(
$x == 32) $base32 .= self::$map[32];
        }
        return
$base32;
    }
   
    public static function
decode($input) {
        if(empty(
$input)) return;
       
$paddingCharCount = substr_count($input, self::$map[32]);
       
$allowedValues = array(6,4,3,1,0);
        if(!
in_array($paddingCharCount, $allowedValues)) return false;
        for(
$i=0; $i<4; $i++){
            if(
$paddingCharCount == $allowedValues[$i] &&
               
substr($input, -($allowedValues[$i])) != str_repeat(self::$map[32], $allowedValues[$i])) return false;
        }
       
$input = str_replace('=','', $input);
       
$input = str_split($input);
       
$binaryString = "";
        for(
$i=0; $i < count($input); $i = $i+8) {
           
$x = "";
            if(!
in_array($input[$i], self::$map)) return false;
            for(
$j=0; $j < 8; $j++) {
               
$x .= str_pad(base_convert(@self::$flippedMap[@$input[$i + $j]], 10, 2), 5, '0', STR_PAD_LEFT);
            }
           
$eightBits = str_split($x, 8);
            for(
$z = 0; $z < count($eightBits); $z++) {
               
$binaryString .= ( ($y = chr(base_convert($eightBits[$z], 2, 10))) || ord($y) == 48 ) ? $y:"";
            }
        }
        return
$binaryString;
    }
}
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1
simon at simonster dot com
19 years ago
Here are some functions for converting integers to and from base 256. Converting to base 64 is simple given these.

<?php
function to_base256($number, $from_base = 10) {
   
$binary_number = base_convert($number, $from_base, 2);
   
$final_string = "";
   
$new_length = (ceil(strlen($binary_number)/8)*8);
   
$binary_number = str_pad($binary_number, $new_length, "0", STR_PAD_LEFT);
    for(
$i=($new_length-8); $i>=0; $i-=8) {
       
$final_string = chr(base_convert(substr($binary_number, $i, 8), 2, 10)).$final_string;
    }
    return
$final_string;
}

function
from_base256($string, $to_base = 10) {
   
$number = "";
    for(
$i=0; $i<strlen($string); $i++) {
       
$number .= str_pad(base_convert(ord($string{$i}), 10, 2), 8, "0", STR_PAD_LEFT);
    }
    return
base_convert($number, 2, $to_base);
}
?>

Yes, I know that this would be more efficient if it used mod instead of base_convert, but it needs to work with integers > 32 bits.
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1
fiftytoo at buckeyeexpress dot com
20 years ago
I needed a function to invert a hex value, which i used for setting font colors when they were on a colored background, that way i will get a contrasting color.

Im sure there are other reasons to use this, you decide!!

<?php
function InvertColor($hex) {
  return
sprintf("%06s",base_convert(($hex ^ 0xFFFFFF),10,16));
  };

print
'<td bgcolor="BB2222"><font color="'.InvertColor(0xBB2222).'">Blah</font></td>';
// Prints 44dddd as the font color, which is it's opposite on the color wheel

?>
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1
bpds
12 years ago
A simple function to convert an int to any base.

<?php
function intToAlphaBaseN($n,$baseArray) {
   
$l=count($baseArray);
   
$s = '';
    for (
$i = 1; $n >= 0 && $i < 10; $i++) {
       
$s $baseArray[($n % pow($l, $i) / pow($l, $i - 1))].$s;
       
$n -= pow($l, $i);
    }
    return
$s;
}

$alpha=array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z');
$r=rand(0, 99999999999);
echo(
intToAlphaBaseN($r,$alpha));
?>
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1
CJ Dennis
17 years ago
Really huge numbers might be truncated at both ends.
eg:
<?php
$binary
="11010101001111010001110101000100011110010110110".
"001111000010001010001111001100011010110110010010011010".
"001011010000001001011111110001010101101101011010101010".
"000100011101110010110010100111110001010010111010110011".
"001111111100011001011011001110001111110000101011010010";
print(
strtoupper(base_convert($binary, 2, 16)));
?>
will output:
9E8EA23CB63C0000000000000000000000000000000000000000000000000000 (64 hex digits)
when the correct result would be:
6A9E8EA23CB63C228F31AD9268B4097F156D6AA11DCB29F14BACCFF196CE3F0AD2 (66 hex digits)
Notice that as well as the result showing '0's after B63C which you would expect it is also missing the first 6A before 9E.
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2
Anonymous
5 years ago
While not immediately clear from the description above, a negative sign is also "silently ignored".

base_convert("-12", 10, 10)   =>   12
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2
ardavies at tiscali dot co dot uk
9 years ago
In order to convert base 26 (hexavigesimal) of just alphanumeric characters (A-Z), wthout integers, (as descibed at http://en.wikipedia.org/wiki/Hexavigesimal), I found this to be useful:

function base_convert_alpha(  $str,  $from,  $to  )
{
    $r = range( 'A', 'Z' );
    $clean = str_replace( $r, array_keys($r), $str );
    return base_convert( $clean, $from, $to );
}

echo base_convert_alpha(  "BAC",  26,  10  );

//$clean = 102 which then returns 678
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1
tika dot pahadi at selu dot edu
8 years ago
Note that the method can only convert max 1024 long numbers. Most people don't nee that but once I ran into an issue where binary string was converted into alphanumeric. In such case, you need to split them, convert them and join.
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0
wadelau at gmail dot com
6 years ago
Base62x gives an alternative way for traditional Base62 and/or Base64.

base62x_encode / base62x_decode would be merged into PHP as an extra module in the future.

Prior to that, users can download the PHP extra module via: https://github.com/wadelau/Base62x
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0
liams dot test dot acc at gmail dot com
8 years ago
I wrote this as part of a college assignment to shorten urls. It works for any base and with any range of characters, eg. A-Za-z0-9 etc. Hope it helps someone.

<?php

        $base
= range(0, 1);
       
$number = 255;

        function
translate($base, $number){

               
$array = array();
               
$n = count($base);
               
$i = $number;

                while(
true){

               
/* by dividing $i % $n we can get the remainder after the number has
                 * been divided by the base. Subtracting the result from $i (number), and dividing
                 * by $n (base) we reassign the result to $i, thus moving on to the next smallest
                 * exponent, and around for another go of the loop. It continues doing this, churning
                 * out the remainders until $i <= 0 at which point it breaks.
                 */
                       
                       
if($i <= 0){

                                break;
                        }else{
                               
$r = ($i % $n);

                             
//reassign the value of $i
                               
$i = ($i - $r) / $n;

                               
$array[] = $base[$r];
                        }
                }
               
$string = implode("", $array);
                return
$string;
        }

       
$string = translate($base, $number);
        echo
$string;
       
       
// prints 11111111
?
up
-1
ohcc at 163 dot com
6 years ago
<?php
    $v
= base_convert(3.14, 10, 10);
   
var_dump($v);
?>

output: string(3) "314"
up
0
denik dot od at gmail dot com
10 years ago
Convert any length bits to HEX:

function bits2hex($bin)
{
   $out = "";
   for($i=0;$i<strlen($bin);$i+=8)
   {
      $byte = substr($bin,$i,8); if( strlen($byte)<8 ) $byte .= str_repeat('0',8-strlen($byte));
      $out .= base_convert($byte,2,16);
   }
   return $out;
}

VARNING! If the last byte is incomplete, it is supplemented with zeros as string!
up
-2
Ray Paseur sometimes uses GMail
17 years ago
[EDIT BY danbrown AT php DOT net: This function provides conversion of Arabic numerals (those used by most of the world, the standard 1,2,3,4,...) into Roman numerals (I,II,III,IV,...).  The original author failed to provide a description, but due to the usefulness of the function, it is being preserved from deletion, and a simple description added.]

<?php
function roman_numerals($input_arabic_numeral='') {

    if (
$input_arabic_numeral == '') { $input_arabic_numeral = date("Y"); } // DEFAULT OUTPUT: THIS YEAR
   
$arabic_numeral            = intval($input_arabic_numeral);
   
$arabic_numeral_text    = "$arabic_numeral";
   
$arabic_numeral_length    = strlen($arabic_numeral_text);

    if (!
ereg('[0-9]', $arabic_numeral_text)) {
return
false; }

    if (
$arabic_numeral > 4999) {
return
false; }

    if (
$arabic_numeral < 1) {
return
false; }

    if (
$arabic_numeral_length > 4) {
return
false; }

   
$roman_numeral_units    = $roman_numeral_tens        = $roman_numeral_hundreds        = $roman_numeral_thousands        = array();
   
$roman_numeral_units[0]    = $roman_numeral_tens[0]    = $roman_numeral_hundreds[0]    = $roman_numeral_thousands[0]    = ''; // NO ZEROS IN ROMAN NUMERALS

   
$roman_numeral_units[1]='I';
   
$roman_numeral_units[2]='II';
   
$roman_numeral_units[3]='III';
   
$roman_numeral_units[4]='IV';
   
$roman_numeral_units[5]='V';
   
$roman_numeral_units[6]='VI';
   
$roman_numeral_units[7]='VII';
   
$roman_numeral_units[8]='VIII';
   
$roman_numeral_units[9]='IX';

   
$roman_numeral_tens[1]='X';
   
$roman_numeral_tens[2]='XX';
   
$roman_numeral_tens[3]='XXX';
   
$roman_numeral_tens[4]='XL';
   
$roman_numeral_tens[5]='L';
   
$roman_numeral_tens[6]='LX';
   
$roman_numeral_tens[7]='LXX';
   
$roman_numeral_tens[8]='LXXX';
   
$roman_numeral_tens[9]='XC';

   
$roman_numeral_hundreds[1]='C';
   
$roman_numeral_hundreds[2]='CC';
   
$roman_numeral_hundreds[3]='CCC';
   
$roman_numeral_hundreds[4]='CD';
   
$roman_numeral_hundreds[5]='D';
   
$roman_numeral_hundreds[6]='DC';
   
$roman_numeral_hundreds[7]='DCC';
   
$roman_numeral_hundreds[8]='DCCC';
   
$roman_numeral_hundreds[9]='CM';

   
$roman_numeral_thousands[1]='M';
   
$roman_numeral_thousands[2]='MM';
   
$roman_numeral_thousands[3]='MMM';
   
$roman_numeral_thousands[4]='MMMM';

    if (
$arabic_numeral_length == 3) { $arabic_numeral_text = "0" . $arabic_numeral_text; }
    if (
$arabic_numeral_length == 2) { $arabic_numeral_text = "00" . $arabic_numeral_text; }
    if (
$arabic_numeral_length == 1) { $arabic_numeral_text = "000" . $arabic_numeral_text; }

   
$anu = substr($arabic_numeral_text, 3, 1);
   
$anx = substr($arabic_numeral_text, 2, 1);
   
$anc = substr($arabic_numeral_text, 1, 1);
   
$anm = substr($arabic_numeral_text, 0, 1);

   
$roman_numeral_text = $roman_numeral_thousands[$anm] . $roman_numeral_hundreds[$anc] . $roman_numeral_tens[$anx] . $roman_numeral_units[$anu];
return (
$roman_numeral_text);
}
?>
up
-2
francesco[at]paladinux.net
13 years ago
base convert is limited on standard base invented.
In some case, if you want to invented some translate code (for authorizion code 4 example) , I hope is usefull this example of base_convert-AS from decimal in 65imal base for a speedCode.
Some more specifical: you can transform using a db
$speedCodeDEC            = $idAziendaMittente.$idAziendaDestinatario.$idDDT ;

//$speedCodeDEC = 3000;

//
$BASECODE = array();
$BASECODE['items'] = 65;
$BASECODE[1]='1';
$BASECODE[2]='2';
$BASECODE[3]='3';
$BASECODE[4]='4';
....
$BASECODE[10]='a';
$BASECODE[11]='b';
$BASECODE[12]='c';
...
$BASECODE[36]='A';
$BASECODE[37]='B';
$BASECODE[38]='C';
...
$BASECODE[61]='Z';
$BASECODE[62]='/';
$BASECODE[63]='-';
$BASECODE[64]='+';
//

//print_r ($BASECODE);TEST

function creaSpeedCode ( $speedCodeDEC,$partialCode="",$BASECODE){

    @$division      = $speedCodeDEC/$BASECODE['items'];
    @$resultINT   = floor($speedCodeDEC/$BASECODE['items']);
    @$remnant          = $speedCodeDEC%$BASECODE['items'];
    $partialCode  = $BASECODE[$remnant].$partialCode;
echo "
    <br>
    Inserito speedCodeDEC:$speedCodeDEC - partialCode:$partialCode<br>
    items            : ".$BASECODE['items']."<br>
    division          : $division    <br>
    resultINT        : $resultINT    <br>
    remnant            : $remnant        <br>
    partialCode        : $partialCode    <br>
";//TEST   
    if ($resultINT > 65)     $partialCode = creaSpeedCode($resultINT,$partialCode,$BASECODE);
    return $BASECODE[$resultINT].$partialCode;
}
echo $speedCodeDEC."<br>";
echo $risultato = creaSpeedCode ( $speedCodeDEC,"",$BASECODE);
up
-4
Baji dot Panchumarti at gmail dot com
11 years ago
Extending base_convert to bases above 36, up to base 62.

<?php
function base_convert_x( $_number='', $_frBase=10, $_toBase=62 ) {

#   Today's Date - C74 - convert a string (+ve integer) from any arbitrary base to any arbitrary base, up to base 62, using  0-9,A-Z,a-z
#
#   Usage :   echo base_convert_x( 123456789012345, 10, 32 );

 
$_10to62 =  array(
   
'0'  => '0', '1'  => '1', '2'  => '2', '3'  => '3', '4'  => '4', '5'  => '5', '6'  => '6', '7'  => '7', '8'  => '8', '9'  => '9', '00' => '0', '01' => '1', '02' => '2', '03' => '3', '04' => '4', '05' => '5', '06' => '6', '07' => '7',
   
'10' => 'A', '11' => 'B', '12' => 'C', '13' => 'D', '14' => 'E', '15' => 'F', '16' => 'G', '17' => 'H', '18' => 'I', '19' => 'J', '20' => 'K', '21' => 'L', '22' => 'M', '23' => 'N', '24' => 'O', '25' => 'P', '26' => 'Q', '27' => 'R',
   
'30' => 'U', '31' => 'V', '32' => 'W', '33' => 'X', '34' => 'Y', '35' => 'Z', '36' => 'a', '37' => 'b', '38' => 'c', '39' => 'd', '40' => 'e', '41' => 'f', '42' => 'g', '43' => 'h', '44' => 'i', '45' => 'j', '46' => 'k', '47' => 'l',
   
'50' => 'o', '51' => 'p', '52' => 'q', '53' => 'r', '54' => 's', '55' => 't', '56' => 'u', '57' => 'v', '58' => 'w', '59' => 'x', '60' => 'y', '61' => 'z'  );

 
$_62to10 =  array(
   
'0' => '00', '1' => '01', '2' => '02', '3' => '03', '4' => '04', '5' => '05', '6' => '06', '7' => '07', '8' => '08', '9' => '09', 'A' => '10', 'B' => '11', 'C' => '12', 'D' => '13', 'E' => '14', 'F' => '15', 'G' => '16', 'H' => '17',
   
'K' => '20', 'L' => '21', 'M' => '22', 'N' => '23', 'O' => '24', 'P' => '25', 'Q' => '26', 'R' => '27', 'S' => '28', 'T' => '29', 'U' => '30', 'V' => '31', 'W' => '32', 'X' => '33', 'Y' => '34', 'Z' => '35', 'a' => '36', 'b' => '37',
   
'e' => '40', 'f' => '41', 'g' => '42', 'h' => '43', 'i' => '44', 'j' => '45', 'k' => '46', 'l' => '47', 'm' => '48', 'n' => '49', 'o' => '50', 'p' => '51', 'q' => '52', 'r' => '53', 's' => '54', 't' => '55', 'u' => '56', 'v' => '57',
   
'y' => '60', 'z' => '61' );

#   ---- First convert from frBase to base-10

   
$_in_b10        =   0;
   
$_pwr_of_frB    =   1;                        #  power of from base, eg. 1, 8, 64, 512
   
$_chars         =   str_split( $_number );    #  split input # into chars
   
$_str_len       =   strlen( $_number );
   
$_pos           =   0;

    while     ( 
$_pos++ < $_str_len )  {
       
$_char          =   $_chars[$_str_len - $_pos];
       
$_in_b10       +=   (((int) $_62to10[$_char] ) * $_pwr_of_frB);
       
$_pwr_of_frB   *=   $_frBase;
    }

#   ---- Now convert from base-10 to toBase

   
$_dividend      =   (int)   $_in_b10;         #  name dividend easier to follow below
   
$_in_toB        =   '';                       #  number string in toBase

   
while     ( $_dividend > 0 )        {

       
$_quotient  =   (int) ( $_dividend / $_toBase );    #  eg. 789 / 62  =  12  ( C in base 62 )
       
$_remainder =   ''  .  ( $_dividend % $_toBase );   #  789 % 62  =  45  ( j in base 62 )
       
$_in_toB    =   $_10to62[$_remainder] . $_in_toB;   #  789  (in base 10)  =    Cj  (in base 62)
       
$_dividend  =   $_quotient;                         #  new dividend is the quotient from base division
   
}

    if  (
$_in_toB  ==  '' )
         
$_in_toB  =   '0';

    return   
$_in_toB;                           #  base $_toBase string
}
#   --------- examples -------
   
echo base_convert_x( '3456789ABCDEF', 16, 10 ) . "\n";    #  920735923817967
   
echo   base_convert( '3456789ABCDEF', 16, 10 ) . "\n";    #  920735923817967
?>
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