hexdec
(PHP 4, PHP 5)
hexdec — Hexadecimal to decimal
Description
Returns the decimal equivalent of the hexadecimal number
represented by the hex_string argument.
hexdec() converts a hexadecimal string to a
decimal number.
hexdec() will ignore any non-hexadecimal characters it encounters.
Parameters
-
hex_string -
The hexadecimal string to convert
Return Values
The decimal representation of hex_string
Changelog
| Version | Description |
|---|---|
| 4.1.0 | The function can now convert values that are too big for the platforms integer type, it will return the value as float instead in that case. |
Examples
Example #1 hexdec() example
<?php
var_dump(hexdec("See"));
var_dump(hexdec("ee"));
// both print "int(238)"
var_dump(hexdec("that")); // print "int(10)"
var_dump(hexdec("a0")); // print "int(160)"
?>
See Also
- dechex() - Decimal to hexadecimal
- bindec() - Binary to decimal
- octdec() - Octal to decimal
- base_convert() - Convert a number between arbitrary bases
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Коментарии
From color to color to ...... to color with fade effect. Good for dynamic bar chart.
<?php
//MultiColorFade(array hex-colors, int steps)
function MultiColorFade($hex_array, $steps) {
$tot = count($hex_array);
$gradient = array();
$fixend = 2;
$passages = $tot-1;
$stepsforpassage = floor($steps/$passages);
$stepsremain = $steps - ($stepsforpassage*$passages);
for($pointer = 0; $pointer < $tot-1 ; $pointer++) {
$hexstart = $hex_array[$pointer];
$hexend = $hex_array[$pointer + 1];
if($stepsremain > 0){
if($stepsremain--){
$stepsforthis = $stepsforpassage + 1;
}
}else{
$stepsforthis = $stepsforpassage;
}
if($pointer > 0){
$fixend = 1;
}
$start['r'] = hexdec(substr($hexstart, 0, 2));
$start['g'] = hexdec(substr($hexstart, 2, 2));
$start['b'] = hexdec(substr($hexstart, 4, 2));
$end['r'] = hexdec(substr($hexend, 0, 2));
$end['g'] = hexdec(substr($hexend, 2, 2));
$end['b'] = hexdec(substr($hexend, 4, 2));
$step['r'] = ($start['r'] - $end['r']) / ($stepsforthis);
$step['g'] = ($start['g'] - $end['g']) / ($stepsforthis);
$step['b'] = ($start['b'] - $end['b']) / ($stepsforthis);
for($i = 0; $i <= $stepsforthis-$fixend; $i++) {
$rgb['r'] = floor($start['r'] - ($step['r'] * $i));
$rgb['g'] = floor($start['g'] - ($step['g'] * $i));
$rgb['b'] = floor($start['b'] - ($step['b'] * $i));
$hex['r'] = sprintf('%02x', ($rgb['r']));
$hex['g'] = sprintf('%02x', ($rgb['g']));
$hex['b'] = sprintf('%02x', ($rgb['b']));
$gradient[] = strtoupper(implode(NULL, $hex));
}
}
$gradient[] = $hex_array[$tot-1];
return $gradient;
}
//end MultiColorFade()
//start test
$multi_hex_array = array();
$multi_hex_array[] = array('FF0000','FFFF00');
$multi_hex_array[] = array('FF0000','FFFF00','00FF00');
$multi_hex_array[] = array('FF0000','FFFF00','00FF00','00FFFF');
$multi_hex_array[] = array('FF0000','FFFF00','00FF00','00FFFF','0000FF');
$multi_hex_array[] = array('FF0000','FFFF00','00FF00','00FFFF','0000FF','000000');
$multi_hex_array[] = array('FF0000','FFFF00','00FF00','00FFFF','0000FF','000000','FFFFFF');
foreach($multi_hex_array as $hex_array){
$totcolors = count($hex_array);
$steps = 44;
$a = MultiColorFade($hex_array, $steps);
$tot = count($a);
$table = '<table border=1 width="300">' . "\n";
for ($i = 0; $i < $tot; $i++){
$table .= ' <tr><td bgcolor="' . $a[$i] . '">' . ($i+1) .'</td><td><pre>' . $a[$i] . '</pre></td></tr>' . "\n";
}
$table .= '</table><br /><br />';
echo '<br />Demanded steps = ' . $steps . '<br />';
echo 'Returned steps = ' . $tot;
if($steps == $tot){
echo '<br />OK.' . $steps . ' = ' . $tot . '<br />';
}else{
echo '<br /><span style="color:#FF0000">FAILED! Demanded steps and returned steps are NOT equal!: ' . $steps . ' != ' . $tot . '</span><br />';
}
echo $table;
}
//end test
?>
Repley.
Use this function to convert a hexa decimal color code to its RGB equivalent. Unlike many other functions provided here, it will work correctly with hex color short hand notation.
Also, if a proper hexa decimal color value is given (6 digits), it uses bit wise operations for faster results.
For eg: #FFF and #FFFFFF will produce the same result
<?php
/**
* Convert a hexa decimal color code to its RGB equivalent
*
* @param string $hexStr (hexadecimal color value)
* @param boolean $returnAsString (if set true, returns the value separated by the separator character. Otherwise returns associative array)
* @param string $seperator (to separate RGB values. Applicable only if second parameter is true.)
* @return array or string (depending on second parameter. Returns False if invalid hex color value)
*/
function hex2RGB($hexStr, $returnAsString = false, $seperator = ',') {
$hexStr = preg_replace("/[^0-9A-Fa-f]/", '', $hexStr); // Gets a proper hex string
$rgbArray = array();
if (strlen($hexStr) == 6) { //If a proper hex code, convert using bitwise operation. No overhead... faster
$colorVal = hexdec($hexStr);
$rgbArray['red'] = 0xFF & ($colorVal >> 0x10);
$rgbArray['green'] = 0xFF & ($colorVal >> 0x8);
$rgbArray['blue'] = 0xFF & $colorVal;
} elseif (strlen($hexStr) == 3) { //if shorthand notation, need some string manipulations
$rgbArray['red'] = hexdec(str_repeat(substr($hexStr, 0, 1), 2));
$rgbArray['green'] = hexdec(str_repeat(substr($hexStr, 1, 1), 2));
$rgbArray['blue'] = hexdec(str_repeat(substr($hexStr, 2, 1), 2));
} else {
return false; //Invalid hex color code
}
return $returnAsString ? implode($seperator, $rgbArray) : $rgbArray; // returns the rgb string or the associative array
} ?>
OUTPUT:
hex2RGB("#FF0") -> array( red =>255, green => 255, blue => 0)
hex2RGB("#FFFF00) -> Same as above
hex2RGB("#FF0", true) -> 255,255,0
hex2RGB("#FF0", true, ":") -> 255:255:0