I am trying to represent a character by its hex value inside a string. It works if hex is explicit but does not work when hex variable is used:
$hex = '5A';
echo "Hex explicit: \x5A, Hex evaluated: \x$hex";
The output is:
Hex explicit: Z, Hex evaluated: \x5A
The question is - how do I modify \x$hex to get Z instead of \x5A?
asked Sep 4, 2013 at 5:00
Dmitri ZaitsevDmitri Zaitsev
13k10 gold badges71 silver badges107 bronze badges
Hope this helps.
Integer literals
This is the answer
$hex = chr[0x5A];
echo "Hex explicit: \x5A, Hex evaluated:".$hex;
or
$hex = chr[0x5A];
echo "Hex explicit: \x5A, Hex evaluated: $hex";
Try this link //www.w3schools.com/php/func_string_chr.asp
answered Sep 4, 2013 at 5:08
Harsha JayamannaHarsha Jayamanna
2,0604 gold badges23 silver badges40 bronze badges
6
[PHP 4, PHP 5, PHP 7, PHP 8]
hexdec — Hexadecimal to decimal
Description
hexdec[string $hex_string]: int|float
hexdec[] will ignore any non-hexadecimal characters it encounters. As of PHP 7.4.0 supplying any invalid characters is deprecated.
Parameters
hex_stringThe hexadecimal string to convert
Return Values
The decimal representation of hex_string
Changelog
| 7.4.0 | Passing invalid characters will now generate a deprecation notice. The result will still be computed as if the invalid characters did not exist. |
Examples
Example #1 hexdec[] example
Notes
Note:
The function can convert numbers that are too large to fit into the platforms int type, larger values are returned as float in that case.
See Also
- dechex[] - Decimal to hexadecimal
- bindec[] - Binary to decimal
- octdec[] - Octal to decimal
- base_convert[] - Convert a number between arbitrary bases
hafees at msn dot com ¶
12 years ago
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
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
programacion at mundosica dot com ¶
10 years ago
Here is other function to transform a MAC Address to decimal:
flurinj at gmx dot net ¶
12 years ago
Here My version of converting a hex string to a signed decimal value:
brian at sagesport dot com ¶
17 years ago
The issue I've seen with the existing hex to dec conversion routines is the lack of error-trapping. I stick to the theory that one should try to cover ALL the bases when writing a generalized routine such as this one. I have a varied background that covers a wide variety of design/development languages, on the web as well as desktop apps. As such I've seen multiple formats for writing hex colors.
For example, the color red COULD be written as follows:
#ff0000
&Hff0000
#ff
&Hff
Therefore I have written a function that is case-insensitive and takes into account the chance that different developers have a tendency to format hex colors in different ways.
"strip_chars" is a support function written to remove the unwanted characters from the hex string, and sends the concatenated string back to the calling function. It will accept either a single value or an array of values for the characters to remove.
As you can see, the function "convert_color" accepts a hex # in most acceptable formats and returns an associative array. [success] is set to TRUE if the function succeeds and FALSE if not. The array members [r], [g] and [b] hold the red,green and blue values respectively. If it fails, [error] holds a custom error message.
chuckySTAR ¶
13 years ago
Here's my hexdec function for greater numbers using BC Math
k10206 at naver dot com ¶
14 years ago
Halit YEL - halityesil at globya dot net ¶
12 years ago
RGB to Hex
Hex to RGB
Function
#FFFFFF =>
#FFCCEE =>
0 65 255 => #0041FF
[EDIT BY danbrown AT php DOT net - Contains multiple bugfixes by [ajim1417 AT gmail DOT com] on 27-JAN-2010: Replaces typo in explode[] and updates eregi[] calls to preg_match[].]
Output
Array{
red=>255,
green=>255,
blue=>255,
r=>255,
g=>255,
b=>255,
0=>255,
1=>255,
2=>255
}
Array{
red=>255,
green=>204,
blue=>238,
r=>255,
g=>204,
b=>238,
0=>255,
1=>204,
2=>238
}
CC22FF =>
Array{
red=>204,
green=>34,
blue=>255,
r=>204,
g=>34,
b=>255,
0=>204,
1=>34,
2=>255
}
255.150.3 => #FF9603
100,100,250 => #6464FA
Anonymous ¶
17 years ago
I wondered long time what is the best way to generate RGB-color from HEX-color, and just now i found the simpliest way!
I hope this will save your time! :]
Walter Wlodarski ¶
14 years ago
One of my favourite, multi-purpose, bidirectional solution I wrote many years ago:
function bgr2rgb[$cr] { // bidirectional
return [[$cr & 0x0000FF] > 16];
}
Which you might want to use as :
function hex2cr[$hex] { // strips any leading characters, like #
return bgr2rgb[hexdec[$hex]];
}
function cr2hex[$cr] { // the usual HTML format, #rrggbb
return '#'.str_pad[strtoupper[dechex[bgr2rgb[$cr]]], 6, '0', STR_PAD_LEFT];
}
And, if like me you tend to mistype function names, the synonym :
function rgb2bgr[$val] { return bgr2rgb[$val]; }
sneskid at hotmail dot com ¶
10 years ago
If you want to create or parse signed Hex strings:
Also note that ['0x' . $hexstr + 0] is faster than hexdec[]
[Tested on PHP v5.2.17]
jose dot rob dot jr at gmail dot com ¶
13 years ago
I made these functions to pack up to 64 ID's into a mysql unsigned bigint.
ID's cannot repeat, must be
Have fun ;D
Ultimater at gmail dot com ¶
13 years ago
hexdec doesn't accept numbers following the period.
What if you have a number like c20.db18?
helpmedalph at gmail dot com ¶
6 years ago
function hex2rgb[$hex] {
if [$hex[0]=='#'] $hex = substr[$hex,1];
if [strlen[$hex]==3]{
$hex = $hex[0].$hex[0].$hex[1].$hex[1].$hex[2].$hex[2];
}
$int = hexdec[$hex];
return array["red" => 0xFF & [$int >> 0x10], "green" => 0xFF & [$int >> 0x8], "blue" => 0xFF & $int];
}
chrism at four dot net ¶
20 years ago
hexdec from 4.1.0 onwards does not show
the same size limitation and therefore
works differently with large numbers than previous php versions.
To obtain the same results, use:
[int] hexdec [...]
joquius at kakugo dot com ¶
14 years ago
Help a hex-stricken string get back to normal:
Anonymous ¶
14 years ago
// Função GET Cor Hexadecima e Retorna em RGB
function hexrgb[$hexstr, $rgb] {
$int = hexdec[$hexstr];
switch[$rgb] {
case "r":
return 0xFF & $int >> 0x10;
break;
case "g":
return 0xFF & [$int >> 0x8];
break;
case "b":
return 0xFF & $int;
break;
default:
return array[
"r" => 0xFF & $int >> 0x10,
"g" => 0xFF & [$int >> 0x8],
"b" => 0xFF & $int
];
break;
}
}// END GET Cor Hex => RGB
//Uso
echo hexrgb["1a2b3c", r]; // 26
echo hexrgb["1a2b3c", g]; // 43
echo hexrgb["1a2b3c", b]; // 60
//ou
var_dump[hexrgb["1a2b3c", rgb]]; //array[3] { ["r"]=> int[26] ["g"]=> int[43] ["b"]=> int[60] }
Manithu ¶
15 years ago
This tiny function will return foreground colors [either black or white] in contrast to the color you provide:
This function will return the opposite [negative]:
cgarvis at gmail dot com ¶
15 years ago
Here is my version of hex2rgb for web colors to 24bit colors.
repley at freemail dot it ¶
16 years ago
From color to color to ...... to color with fade effect. Good for dynamic bar chart.
Repley.
cory at lavacube dot com ¶
16 years ago
A handy little function to convert HEX colour codes to "web safe" colours...
Hope this helps someone out... Happy coding. :-]
Example: color_mkwebsafe['0e5c94'];
Produces: 006699
detrate at hotmail dot com ¶
16 years ago
I made this for a little phpbb mod. It was used to take the hex value from the database and make a color 20 [in decimal] less, resulting a darker color.
EXAMPLE: #336699 to #1f5285
Gabriel Reguly ¶
17 years ago
After esnhexdec from "rledger at gmail dot com", the esndechex:
bishop ¶
17 years ago
Bullet-proof hex-to-rgb colour converter like brian at sagesport dot com wanted, just far fewer code lines. As a bonus, gives you the ability to return as string or array:
Handles 2, 3, and 6 character colour codes with leading # or &H.
zubfatal, root at it dot dk ¶
17 years ago
This replaces my previous class.
I've added a few more input checks in the rgb2hex function.
Also it returned incorrect hex values for 1-digit values.
color::rgb2hex[array[0,0,0]] would output 000 not 00000.
groobo ¶
17 years ago
It's just a revision to marfastic's ligten_up script, it simply adds/subtracts mod_color to orig_color.
I use it often to adjust tonals rather than brightness only
this1is4me at hotmail dot com ¶
14 years ago
In reply to Amit Yadav's post [hex to binary conversion]:
function binfromdec[$num]
{
$primary = "bit";
for [$i=1; $i
Rosberg - rosberglinhares at gmail dot com ¶
12 years ago
The correct version is:
function bchexdec[$hex] {
static $hexdec = 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
];
$dec = 0;
for [$i = strlen[$hex] - 1, $e = 1; $i >= 0; $i--, $e = bcmul[$e, 16]] {
$factor = $hexdec[$hex[$i]];
$dec = bcadd[$dec, bcmul[$factor, $e]];
}
return $dec;
}