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Digg  dechex
Decimal to hexadecimal
(PHP 4, PHP 5)
Example 1143. dechex() example<?phpThe above example will output: aRelated Examples ( Source code ) » dechex Examples ( Source code ) » Generating a Web-Safe Color Palette Examples ( Source code ) » dechex Examples ( Source code ) » hexdec Code Examples / Notes » dechexpaoligno
you can use this workaround (raw but simple and efficient) $string=DecHex($string*1) bye bye oliver
Warning for use on 64 bit machines! The Extra length matters! 32bit machine: php -r 'echo dechex(4294967295);' output: ffffffff 64bit machine: php -r 'echo dechex(4294967295);' output: ffffffff so far it is ok. But for slightly bigger numbers: 32bit machine: php -r 'echo dechex(4294967296);' output: 0 64bit machine: php -r 'echo dechex(4294967296);' output: 100000000 note the difference! This is particularly important when converting negative numbers: 64bit machine: php -r 'echo dechex(-1);' output: ffffffffffffffff 32bit machine: php -r 'echo dechex(-1);' output: ffffffff If you want your code to be portable to amd64 or xeons (which are now quite popular with hosting companies) then you must ensure that your code copes with the different length of the result for negative numbers (and the max value, although that is probably less critical). gurke
usefull if you need to convert decimal colors to html style hex colors: function hexColor($color) { return sprintf("%02X%02X%02X",$color[0],$color[1],$color[2]); } example: $col[0] = 25; $col[1] = 255; $col[2] = 55; print hexColor($col); sjaak
To force the correct usage of 32-bit unsigned integer in some functions, just add '+0' just before processing them. for example echo(dechex("2724838310")); will print '7FFFFFFF' but it should print 'A269BBA6' When adding '+0' php will handle the 32bit unsigned integer correctly echo(dechex("2724838310"+0)); will print 'A269BBA6' m0sh3
This will can convert decimal of more than 2^48 in any PHP version: $hex = dechex($dec>>24).dechex($dec & 0xFFFFFF) wangster
This function will take a string and convert it into a hexdump. e.g. 3c666f6e 74207369 7a653d22 33223e4c <font.size."3">L 6561726e 20686f77 20746f20 62652061 earn.how.to.be.a function hexdump($string) { $hex=""; $substr = ""; for ($i=0; $i < strlen($string) ;$i++) { if(!($i % 4) && $i != 0) { $hex .= " "; } if(!($i % 16) && $i != 0) { $clean = preg_replace("/[^a-zA-Z0-9!-.<>\/]/",".",$substr); $hex .= " ".htmlentities($clean)."\n"; $substr = ""; } $substr .= $string[$i]; $hex .= dechex(ord($string[$i])); } return $hex; } ruben barkow
this function generates an hex-colorcode out of a string. usefull if you want to show a list of words all in different colors, that should remain its color even if the order changes. (if the string is empty, it gives back a random color) function word2color($w){ if (strlen($w)==0) return substr('00000' . dechex(mt_rand(0, 0xffffff)), -6); while (strlen($w)<6) $w.=$w; $minbrightness=1; // range from 0 to 15, if this is 0 then for ex. black is allowed $max_brightness=14; // range from 0 to 15, if this is 15 then for ex. white is allowed $plus_red=0; // set one of these to set the probability of one of these colors higher $plus_green=0; $plus_blue=0; for ($i=0; $i<6; $i++) { #$r.= '">';// this is a depug mode, to see the color written $plus=0; if ($plus_red<>0 and $i==0) $plus=$plus_red; if ($plus_green<>0 and $i==2) $plus=$plus_green; if ($plus_blue<>0 and $i==4) $plus=$plus_blue; $c=$w[round(strlen($w)/6*$i)]; $dec=ord($c)%($max_brightness+$plus-$minbrightness) +$minbrightness+$plus; if ($dec>$max_brightness-$minbrightness) $dec=$max_brightness-$minbrightness; $r.= strtoupper( dechex($dec) ); } return $r; } mista-niceguy
These are functions to convert roman numbers (e.g. MXC) into dec and vice versa. Note: romdec() does not check whether a string is really roman or not. To force a user-input into a real roman number use decrom(romdec($input)). This will turn XXXX into XL for example. <?php function decrom($dec){ $digits=array( 1 => "I", 4 => "IV", 5 => "V", 9 => "IX", 10 => "X", 40 => "XL", 50 => "L", 90 => "XC", 100 => "C", 400 => "CD", 500 => "D", 900 => "CM", 1000 => "M" ); krsort($digits); $retval=""; foreach($digits as $key => $value){ while($dec>=$key){ $dec-=$key; $retval.=$value; } } return $retval; } function romdec($rom){ $digits=array( "I" => 1, "V" => 5, "X" => 10, "L" => 50, "C" => 100, "D" => 500, "M" => 1000 ); $retval=""; $chars=array(); for($i=1;$i<=strlen($rom);$i++){ $chars[]=substr($rom,$i-1,1); } $step=1; for($i=count($chars)-1;$i>=0;$i--){ if(!isset($digits[$chars[$i]])){ return "Error!"; } if($step<=$digits[$chars[$i]]){ $step=$digits[$chars[$i]]; $retval+=$digits[$chars[$i]]; } else{ $retval-=$digits[$chars[$i]]; } } return $retval; } echo decrom(romdec("XXXX")); ?> poj
The rgbhex function by AsakuraStar won't work for small values, eg (15,15,15) should return 0F0F0F, not FFF. I suggest the following: <?php function rgbhex($red, $green, $blue) { // force the passed value to be numeric by adding zero // use max and min to limit the number to between 0 and 255 // shift the number to make it the correct future hex value $red = 0x10000 * max(0,min(255,$red+0)); $green = 0x100 * max(0,min(255,$green+0)); $blue = max(0,min(255,$blue+0)); // convert the combined value to hex and zero-fill to 6 digits return "#".str_pad(strtoupper(dechex($red + $green + $blue)),6,"0",STR_PAD_LEFT); } ?> Maybe in future dechex will have a size parameter, as in: dechex($red+$green+$blue , 6) This would especially be useful for negative numbers. dechex(-1 , 2) would then give ff. michael
simple, non-recursive way of zerofilling (why making everything complicated, there r more than enough inbuilt functions) function zfill($n,$a) { return str_repeat("0",max(0,$a-strlen($n))).$n; } "max(0,..." as multiplier inside of "str-repeat" is preventing an error with negative values, if the string length was already higher than the accuracy parameter for zfill. have fun! :) allan-wegan
now, here is a nice and small function to convert integers to hex strings and it avoids use of the DECHEX funtion because that function changed it's behavior too often in the past (now, in PHP version 4.3.2 it works with numbers bigger than 0x7FFFFFFF correctly, but i need to be backward compatible). function &formatIntegerForOutput($value) { $text = "00000000"; $transString = "0123456789ABCDEF"; // handle highest nibble (nibble 7): $nibble = $value & 0x70000000; $nibble >>= 28; if ($value < 0) { $nibble = $nibble | 0x00000008; } $text[0] = $transString[$nibble]; $value &= 0x0FFFFFFF; // nibbles 0 to 6: for ($a = 7; $a > 0; $a --) { $nibble = $value & 0x0000000F; $text[$a] = $transString[$nibble]; $value >>= 4; } return $text } this function should be not too slow and is really simple. I don't know, if the DECHEX function in the future will pad it's output to ever be 8 characters in length - so for backward compatibility reasons even in future PHP versions i avoided to use it. matt dot smith
It took me hours, but I've finally figured it all out... -- To figure up how many lines it'll take to get from, 0000 to FFFF, use this formula: ((hex_length / 2) * 255) + 1 For 0000 to FFFF, this would be: ((4 / 2) * 255) + 1 = 511 For 0000000000 to FFFFFFFFFF, this would be: ((10 / 2) * 255) + 1 = 1276 -- To figure up how many possibilities a certain hex length will give (such as that of an MD5 hash, for example), use this formula: 256^(hex_length / 2) Like so: hex = 0123ABCDEF hex_length = 10 possibilities = 256^(10 / 2) possibilities = 256^5 possibilities = 1,099,511,627,776 -- And I don't know how useful this next part is, but it's quite nifty. Just set $length to be your hex_length and it'll display all "incrementally-possible" hexadecimals, along with line numbers: <?php $length = 10; // Change this to the total length of your hexadecimal function array_check($array1, $array2) { $count1 = count($array1); $count2 = count($array2); if ($count1 != $count2) return FALSE; $match = 0; for ($i = 0; $i < $count1; $i++) if ($array1[$i] == $array2[$i]) $match++; if ($match != $count1) return FALSE; return TRUE; } function zeropad($num) { return (strlen($num) == 1) ? '0'.$num : $num; } function zeropad_lineno($num, $length) { while (strlen($num) < $length) $num = '0'.$num; return $num; } $hexadecimals = $length / 2; $possibilities = /*number_format(*/ pow(256, $hexadecimals) /*)*/; echo "A hexadecimal of this length ({$length}) has {$possibilities} possibilities. \n"; echo " \n"; //init for ($i = 0; $i < $hexadecimals; $i++) { $x[] = '00'; $xint[] = 0; $end[] = 'ff'; } $line = 0; while ( !(array_check($x, $end)) ) // while we're not currently at the end (FF..) { $hexstr = ''; for ($i = 0; $i < $hexadecimals; $i++) { $x[$i] = dechex($xint[$i]); $hexstr .= zeropad(dechex($xint[$i])); } $line++; $linestr = zeropad_lineno($line, 8); echo "<code>{$linestr}: {$hexstr}</code> \n"; // hex increment for ($i = ($hexadecimals - 1); $i >= 0; $i--) { // increment bit if possible if ($xint[$i] != 255) { // increment bit and then break out of the for loop $xint[$i]++; break; } } } ?> manithu
If you want to fade some text from one color to another, use this function: <?php function colorFade($text, $color1, $color2, $HTMLelement = 'span') { //remove leading and trailing whitespaces. $text = trim($text); //split the characters of the text to an array. $char = array(); for ($i = 0; $i < strlen($text); $i++) { $char[$i] = substr($text, $i, 1); } //convert the hexadecimal colors in decimal. $decimalColor = array(); //first color $decimalColor[0] = hexdec(substr($color1, 0, 2)); $decimalColor[1] = hexdec(substr($color1, 2, 2)); $decimalColor[2] = hexdec(substr($color1, 4, 2)); //second color $decimalColor[3] = hexdec(substr($color2, 0, 2)); $decimalColor[4] = hexdec(substr($color2, 2, 2)); $decimalColor[5] = hexdec(substr($color2, 4, 2)); //formated chars are stored here (the key 0 is for the first //char and must not be removed). $newText = array(0 => null); //run over every character except the first and the last, //they will be added later. for ($i = 2; $i <= strlen($text)-1; $i++) { //check if the character is only a whitespace. If yes, //save the whitespace without adding color and proceed //to the next character. if (!trim($char[$i-1])) { $newText[] = $char[$i-1]; continue; } //calculate the (hex) color for this character. $color = array(); //red $color[] = dechex(($decimalColor[0] - $decimalColor[3]) / strlen($text) * $i + $decimalColor[3]); //green $color[] = dechex(($decimalColor[1] - $decimalColor[4]) / strlen($text) * $i + $decimalColor[4]); //blue $color[] = dechex(($decimalColor[2] - $decimalColor[5]) / strlen($text) * $i + $decimalColor[5]); //check if every color part is 2 chars long, if not, repeat it. foreach ($color as $k => $v) { if (strlen($v) < 2) { $color[$k] = str_repeat($v, 2); } } //merge the parts to the full hex color. $color = implode($color, ''); //Save the formated char. $newText[] = '<'.$HTMLelement.' style="color:#'.$color.'">'. $char[$i-1].'</'.$HTMLelement.'>'; } //add first char. $newText[0] = '<'.$HTMLelement.' style="color:#'.$color2.'">'. $char[0].'</'.$HTMLelement.'>'; //add last char. $newText[] = '<'.$HTMLelement.' style="color:#'.$color1.'">'. $char[strlen($text)-1].'</'.$HTMLelement.'>'; //merge the characters and return it. return implode($newText, ''); } ?> $color1 is the start color, $color2 the end color. I hope this helps somebody. asakurastar
If you want a simple function to convert RGB Colors to HEX Colors that you can use on your website, try this: <?php function rgbhex($red,$green,$blue) { $red = dechex($red); $green = dechex($green); $blue = dechex($blue); return "#".strtoupper($red.$green.$blue); } //Let's Check out using the following colors: //Red: 118; Green: 251; Blue: 85 echo rgbhex(118,251,85); //Result: #76FB55 ?> 12-dec-2004 03:31
If you need to generate random HEX-color, use this: <?php function random_hex_color(){ return sprintf("%02X%02X%02X", mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255)); } $hex = random_hex_color(); // 09B826 ?> Enjoy. 11-dec-2004 09:30
If you need to convert RGB-color into HEX-color, use this: <?php function rgb2hex($rgb){ return sprintf("%06X", $rgb); } $hex = rgb2hex(65280); // 00FF00 ?> morten
I see a lot of less-than-optimal functions posted on this page, so I feel I have to give some better examples... due to the sheer size of this collection, I have made it available on my server, rather than copy/paste it into these comments. http://ryo-ohki.4th-age.com/demos/able.php and http://ryo-ohki.4th-age.com/demos/able.phps dechex replacement function from above source: <?php define('BIT_BYTE', 8); // bits per byte define('HEX_BYTE', BIT_BYTE/4); // hex digits in a byte define('BIT_INT', 32); // sizeof(int) define('HEX_INT', BIT_INT / (BIT_BYTE/HEX_BYTE)); // hex digits in an int function i2h($int, $group=HEX_BYTE, $size=HEX_INT, $sep=' ') { $ret = ''; while($size--) { $n=($int>>($size*4)) & 0xf; $ret .= $n>9?chr(55 + $n):$n; if($size && $size%$group == 0) $ret .= $sep; } return $ret; } echo i2h(rand(1,2)==1?-mt_rand():mt_rand()); ?> foros
I leave code blocks them that I have made to be able to replace the content of certain blocks of JS that used eval () I hope serves to them. // Convert hex 2 str // Imput Example: \x68\x6f\x6c\x61\x20\x6d\x75\x6e\x64\x6f $que=( isset( $_POST['hexadecimal'] ) )?$_POST['hexadecimal']:""; $valores=explode( "\\\x", $que ); for ( $i=0; $i<count( $valores ) ; $i++) { echo chr( hexdec( $valores[$i] ) ) ; } // Convert str 2 hex // Imput Example: hola mundo $que=( isset( $_POST['ascii'] ) )?$_POST['ascii']:""; for ( $i=0; $i<strlen( $que ) ; $i++) { echo "\\x".dechex( ord( substr( $que, $i, 1) ) ) ; } kristoffer
Heres a example of dec to html hex gradient. Have fun :) //Amount of gradients $l = 20; //Start color $start[0] = "255"; //red $start[1] = "0"; //green $start[2] = "255"; //blue //End color $end[0] = "255"; //red $end[1] = "255"; //green $end[2] = "255"; //blue for ($t = 1; $t < $l;) { $x = $x * $t; for ($i = 0; $i < 3;) { $buffer[$i] = $start[$i] - $end[$i]; $buffer[$i] = floor($buffer[$i] / $l); $rgb[$i] = $start[$i] - ($buffer[$i] * $t); if ($rgb[$i] > 255) { $rgb[$i] = 255; } $rgb[$i] = dechex($rgb[$i]); $rgb[$i] = strtoupper($rgb[$i]); if (strlen($rgb[$i]) < 2) { $rgb[$i] = "0$rgb[$i]"; } $i++; } $color = "$rgb[0]$rgb[1]$rgb[2]"; echo "$color"; $t++; } ?> daevid
Here's my version of a red->yellow->green gradient: <?php function colorMeter($percent, $invert = false) { //$percent is in the range 0.0 <= percent <= 1.0 // integers are assumed to be 0% - 100% // and are converted to a float 0.0 - 1.0 // 0.0 = red, 0.5 = yellow, 1.0 = green //$invert will make the color scale reversed // 0.0 = green, 0.5 = yellow, 1.0 = red //convert (int)% values to (float) if (is_int($percent)) $percent = $percent * 0.01; $R = min((2.0 * (1.0-$percent)), 1.0) * 255.0; $G = min((2.0 * $percent), 1.0) * 255.0; $B = 0.0; return (($invert) ? sprintf("%02X%02X%02X",$G,$R,$B) : sprintf("%02X%02X%02X",$R,$G,$B)); } //colorMeter ?> and use it like this: <TABLE BORDER=1 WIDTH="300"> <?php for ($i = 0.0; $i <= 1.0; $i += 0.10) { $RGB = colorMeter($i); print "<TR><TD BGCOLOR='".$RGB."'>".$i."</TD><TD> <PRE>".$RGB."</PRE></TD></TR>\n"; } ?> </TABLE> <TABLE BORDER=1 WIDTH="300"> <?php for ($i = 0; $i <= 100; $i += 10) { $RGB = colorMeter(intval($i), true); print "<TR><TD BGCOLOR='".$RGB."'>".$i."</TD><TD> <PRE>".$RGB."</PRE></TD></TR>\n"; } ?> </TABLE> monkynospam
Here's how to use bitwise operations for RGB2hex conversion. This function returns hexadesimal rgb value just like one submitted by gurke@bigfoot.com above. function hexColor($color) { return dechex(($color[0]<<16)|($color[1]<<8)|$color[2]); } example: $col[0] = 25; $col[1] = 255; $col[2] = 55; print hexColor($col); jfren484
Here's a function which works for decimal values up to 9007199254740992 (hex 20000000000000). function dec2hex($dec) { $hex = ($dec == 0 ? '0' : ''); while ($dec > 0) { $hex = dechex($dec - floor($dec / 16) * 16) . $hex; $dec = floor($dec / 16); } return $hex; } admin
Here is a very small zeropadding that you can use for numbers: function zeropad($num, $lim) { return (strlen($num) >= $lim) ? $num : zeropad("0" . $num); } zeropad("234",6); will produce: 000234 zeropad("234",1); will produce: 234 joost
Here are two functions that will convert large dec numbers to hex and vice versa. And I really mean LARGE, much larger than any function posted earlier. <pre> // Input: A decimal number as a String. // Output: The equivalent hexadecimal number as a String. function dec2hex($number) { $hexvalues = array('0','1','2','3','4','5','6','7', '8','9','A','B','C','D','E','F'); $hexval = ''; while($number != '0') { $hexval = $hexvalues[bcmod($number,'16')].$hexval; $number = bcdiv($number,'16',0); } return $hexval; } // Input: A hexadecimal number as a String. // Output: The equivalent decimal number as a String. function hex2dec($number) { $decvalues = array('0' => '0', '1' => '1', '2' => '2', '3' => '3', '4' => '4', '5' => '5', '6' => '6', '7' => '7', '8' => '8', '9' => '9', 'A' => '10', 'B' => '11', 'C' => '12', 'D' => '13', 'E' => '14', 'F' => '15'); $decval = '0'; $number = strrev($number); for($i = 0; $i < strlen($number); $i++) { $decval = bcadd(bcmul(bcpow('16',$i,0),$decvalues[$number{$i}]), $decval); } return $decval; } </pre> c_westerbeek
echo dec2hex(123, 5); will show: 0007b echo dec2hex(708191, 10); will show: 00000ace5f mina86
Easiest :P way to create random hex color: <?php function rand_color() { return substr('00000' . dechex(mt_rand(0, 0xffffff)), -6); } ?> paeppi
Easier way to create random hex color: <?php function rand_color() { $hexcolor = dechex(mt_rand(0,16777215)); while (strlen($hexcolor) < 6) { $hexcolor = $hexcolor."0"; } return $hexcolor; } echo "#".rand_color(); ?> huda m elmatsani
Create Random Hex Color: function make_seed() { list($usec, $sec) = explode(' ', microtime()); return (float) $sec + ((double) $usec * 100000); } function rand_hex() { mt_srand(make_seed()); $randval = mt_rand(0,255); //convert to hex return sprintf("%02X",$randval); } function random_color(){ return "#".rand_hex().rand_hex().rand_hex(); } hme ;) brent
Be very careful calling dechex on a number if it's stored in a string. For instance: The max number it can handle is 4294967295 which in hex is FFFFFFFF, as it says in the documentation. dechex(4294967295) => FFFFFFFF //CORRECT BUT, if you call it on a string of a number, it casts to int, and automatically gives you the largest int it can handle. dechex('4294967295') => 7FFFFFFF //WRONG! so you'll need to cast to a float: dechex((float) '4294967295') => FFFFFFFF //CORRECT This took me FOREVER to figure out, so hopefully I just saved someone some time. geoffrey
As a sum up of some notes already posted here, my own strhex() function: <?php function strhex($string) { $hex = ''; $len = strlen($string); for ($i = 0; $i < $len; $i++) { $hex .= str_pad(dechex(ord($string[$i])), 2, 0, STR_PAD_LEFT); } return $hex; } ?> pinto
And another built-in function str_pad($value, 2, '0', STR_PAD_LEFT); :) jrisken
A less elegant but (perhaps) faster way to pad is with substr with a negative length argument. I use it in this tiny function which formats computed rgb color codes for style sheets: <? function toColor($n) { return("#".substr("000000".dechex($n),-6)); } ?> cory
A handy little function to convert HEX colour codes to "web safe" colours... <?php function color_mkwebsafe ( $in ) { // put values into an easy-to-use array $vals['r'] = hexdec( substr($in, 0, 2) ); $vals['g'] = hexdec( substr($in, 2, 2) ); $vals['b'] = hexdec( substr($in, 4, 2) ); // loop through foreach( $vals as $val ) { // convert value $val = ( round($val/51) * 51 ); // convert to HEX $out .= str_pad(dechex($val), 2, '0', STR_PAD_LEFT); } return $out; } ?> Example: color_mkwebsafe('0e5c94'); Produces: 006699 Hope this helps someone out... Happy coding. :-) c_westerbeek
a dec 2 hex function that goes way beyon 7fffffff. I don't now wat the limit is. float's precision is 14 decimal digits so the precision of dec2hex should be 5AF3107A3FFF (=99999999999999) function dec2hex($number, $length) { $hexval=""; while ($number>0) { $remainder=$number%16; if ($remainder<10) $hexval=$remainder.$hexval; elseif ($remainder==10) $hexval="a".$hexval; elseif ($remainder==11) $hexval="b".$hexval; elseif ($remainder==12) $hexval="c".$hexval; elseif ($remainder==13) $hexval="d".$hexval; elseif ($remainder==14) $hexval="e".$hexval; elseif ($remainder==15) $hexval="f".$hexval; $number=floor($number/16); } while (strlen($hexval)<$length) $hexval="0".$hexval; //this is just to add zero's at the beginning to make hexval a certain length return $hexval; } trance4rm
a bugfix for admin AT bobfrank DOT org' s post The original was: <?php function zeropad($num, $lim) { return (strlen($num) >= $lim) ? $num : zeropad("0" . $num); } ?> I couldn't get it to work, kept getting a "Missing argument 2 for zeropad()" error, even though I called the function with both arguments -- then I noticed the recursive part, and the missing $lim argument. The code that works is: <?php function zeropad($num, $lim) { return (strlen($num) >= $lim) ? $num : zeropad("0" . $num, $lim); // $lim was missing from the recursive call // the function will prefix $num with a zero and recursively call itself // each recursive call, $num gets one digit bigger until strlen of $num equals $lim } ?> jon
@poj and AsakuraStar, You're probably better off doing this instead to get what you want: <?php function rgbhex($red, $green, $blue) { return sprintf('#%02X%02X%02X', $red, $green, $blue); } echo rgbhex(15, 15, 15); // prints #0F0F0F ?> It's cleaner and most likely faster. May not even want to encapsulate it in a function, as it's just a one-liner. thr
/* * RGB-Colorcodes(i.e: 255 0 255) to HEX-Colorcodes (i.e: FF00FF) */ function rgb2hex($rgb){ if(!is_array($rgb) || count($rgb) != 3){ echo "Argument must be an array with 3 integer elements"; return false; } for($i=0;$i<count($rgb);$i++){ if(strlen($hex[$i] = dechex($rgb[$i])) == 1){ $hex[$i] = "0".$hex[$i]; } } return $hex; } /* Example */ print_r(rgb2hex(array(10,255,255))); admin takethisout
<?php /* here are two functions, some might find them useful (maybe for encoding) converting string to hex and hex to string: */ function strhex($string) { $hex=""; for ($i=0;$i<strlen($string);$i++) $hex.=(strlen(dechex(ord($string[$i])))<2)? "0".dechex(ord($string[$i])): dechex(ord($string[$i])); return $hex; } function hexstr($hex) { $string=""; for ($i=0;$i<strlen($hex)-1;$i+=2) $string.=chr(hexdec($hex[$i].$hex[$i+1])); return $string; } ?> the_tenth
<? function dec2hex($number) { $length=16; $hexval=""; while ($number>0) { $remainder=bcmod($number,16); if ($remainder<10) $hexval=$remainder.$hexval; elseif ($remainder==10) $hexval="A".$hexval; elseif ($remainder==11) $hexval="B".$hexval; elseif ($remainder==12) $hexval="C".$hexval; elseif ($remainder==13) $hexval="D".$hexval; elseif ($remainder==14) $hexval="E".$hexval; elseif ($remainder==15) $hexval="F".$hexval; $number=bcdiv($number,16); } while (strlen($hexval)<$length) $hexval="0".$hexval; return $hexval; } $tmp = "<table width='643' border='1'>"; $x = 1; $y = 1; $z = dec2hex($x); $q = dec2hex($y); for ($i=1;$i<65;$i++){ $x= bcpow(2,($i-1)); $z = dec2hex($x); $tmp .="<tr><td width='20' align='center' bgcolor='#808080'><font color='#ffffff'>". $i; $tmp .="</font></td><td width='5'>2<sup>". ($i-1) . "</sup></td><td width='2'>=</td></td><td>" . $x . "</td>"; $tmp .="<td>".$z."</td><td>".$y."</td><td>".$q."</td></tr>"; $y = bcsub(bcpow(2,$i+1),1); $q = dec2hex($y); } $tmp .= "</table>"; echo $tmp; ?> paeppi
# One example how to convert a decimal number into any other system (here 32 digits -- 0 to v) and how to convert back. # Just replace the "32" in my functions with the number of digits in "your" system, and continue the replace-lists. # This is surely not the very best way to do this, but it hopefully helps :-) function decttw($int_dec) { $s = $int_dec; while ($i < 19) { $exp = pow(32,18 - $i); $modulo = fmod($s,$exp); $value = ($s - $modulo) / $exp; if (($value > 0) && ($start != 1)) { $start = 1; } if ($start == 1) { $decs = $value; $decs = ereg_replace ("10", "a", $decs); $decs = ereg_replace ("11", "b", $decs); $decs = ereg_replace ("12", "c", $decs); $decs = ereg_replace ("13", "d", $decs); $decs = ereg_replace ("14", "e", $decs); $decs = ereg_replace ("15", "f", $decs); $decs = ereg_replace ("16", "g", $decs); $decs = ereg_replace ("17", "h", $decs); $decs = ereg_replace ("18", "i", $decs); $decs = ereg_replace ("19", "j", $decs); $decs = ereg_replace ("20", "k", $decs); $decs = ereg_replace ("21", "l", $decs); $decs = ereg_replace ("22", "m", $decs); $decs = ereg_replace ("23", "n", $decs); $decs = ereg_replace ("24", "o", $decs); $decs = ereg_replace ("25", "p", $decs); $decs = ereg_replace ("26", "q", $decs); $decs = ereg_replace ("27", "r", $decs); $decs = ereg_replace ("28", "s", $decs); $decs = ereg_replace ("29", "t", $decs); $decs = ereg_replace ("30", "u", $decs); $decs = ereg_replace ("31", "v", $decs); $int_value = $int_value.$decs; } $s = $s - $value * $exp; $i++; } return $int_value; } function ttwdec($int_ttw) { $digits = strlen($int_ttw); while ($i < $digits) { $s = substr($int_ttw,$i,1); $decs = $s; $decs = ereg_replace ("a", "10", $decs); $decs = ereg_replace ("b", "11", $decs); $decs = ereg_replace ("c", "12", $decs); $decs = ereg_replace ("d", "13", $decs); $decs = ereg_replace ("e", "14", $decs); $decs = ereg_replace ("f", "15", $decs); $decs = ereg_replace ("g", "16", $decs); $decs = ereg_replace ("h", "17", $decs); $decs = ereg_replace ("i", "18", $decs); $decs = ereg_replace ("j", "19", $decs); $decs = ereg_replace ("k", "20", $decs); $decs = ereg_replace ("l", "21", $decs); $decs = ereg_replace ("m", "22", $decs); $decs = ereg_replace ("n", "23", $decs); $decs = ereg_replace ("o", "24", $decs); $decs = ereg_replace ("p", "25", $decs); $decs = ereg_replace ("q", "26", $decs); $decs = ereg_replace ("r", "27", $decs); $decs = ereg_replace ("s", "28", $decs); $decs = ereg_replace ("t", "29", $decs); $decs = ereg_replace ("u", "30", $decs); $decs = ereg_replace ("v", "31", $decs); $i++; $value = $decs * pow(32,($digits - $i)); $int_value = $int_value + $value; } return $int_value; } 22-mar-2001 06:26
# dec2hex function # # For hex numbers that go up to FFFFFFFF (instead of 7FFFFFFF) # # crude but does the job... # function dec2hex($dec) { if($dec > 2147483648) { $result = dechex($dec - 2147483648); $prefix = dechex($dec / 268435456); $suffix = substr($result,-7); $hex = $prefix.str_pad($suffix, 7, "0000000", STR_PAD_LEFT); } else { $hex = dechex($dec); } return($hex); } |
