Two different special characters are equal

Question

I'm trying to compare 2 different special characters, but they are equal when I compare them.

$char1= "";
$char2= "";

echo mb_detect_encoding($char1, 'UTF-8', true); // 'UTF-8'
echo mb_detect_encoding($char2, 'UTF-8', true); // 'UTF-8'

if($char1 == $char2) // TRUE
echo strcmp($char1, $char2); // 0

Apache/2.4.10

PHP/5.6.3

PhpStorm 9.0.2

What can I do to make a valid comparison?

Thank you.

@Anant, copy paste them localy, e.g. Windows start menu (search box), it can read them. — Boy, Jul 17 '16 at 06:21
`var_dump($char1 == $char2)` gives me `FALSE` with your two characters. Can you confirm your result? maybe you could try `strcmp` to do your comparison. It returns `0` if the strings are equal. — BeetleJuice, Jul 17 '16 at 06:27
@BeetleJuice, how? it gives TRUE to me. My PHP script is saved as UTF-8. I also tried binary compare, same result. — Boy, Jul 17 '16 at 06:30
I don't know how. It's strange. I've confirmed my results here: http://sandbox.onlinephpfunctions.com/code/5a3300372aa4cf6c687dfcc15d4004ba07a40d6d — BeetleJuice, Jul 17 '16 at 06:40
@BeetleJuice, Do you maybe know if there is some setting on my server to correct this? — Boy, Jul 17 '16 at 06:44
sorry I don't, but if you find out what's going on, please write up an answer so it will help the next person. — BeetleJuice, Jul 17 '16 at 06:45

score 2 · Accepted Answer · edited May 23 '17 at 12:14

2

What can I do to make a valid comparison?

Updated Solution

Perhaps we're looking at this the wrong way. The problem may have nothing to do with PHP, but be about your code editor instead. Perhaps the editor is registering both chars as the same when you enter them, so PHP doesn't see any difference. Here is what you can do:

Save each char in a file by itself, using an editor that recognizes the character, such as Wordpad
Load the character in PHP with $char=file_get_contents('path/to/char.txt')
Now that we've bypassed your code editor entirely, compare the two. If they're different, your editor might be to blame.

Original Solution

You could try to convert your characters to their ASCII values and compare the values instead of the characters

$ordUTF8 = function($char){
    list(, $ord) = unpack('N', mb_convert_encoding($char, 'UCS-4BE', 'UTF-8'));
    return $ord;
};
$char1= "";
$char2= "";
// 61656 and 61558 in my testing
$isEqual = $ordUTF8($char1)===$ordUTF8($char2);

Live demo. This solution was inspired by this accepted answer

edited May 23 '17 at 12:14

Community

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answered Jul 17 '16 at 06:57

BeetleJuice

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Returns true... :( – Boy Jul 17 '16 at 06:59
1

Perhaps we're looking at it from the wrong angle. Maybe it has to do with your code editor? What if you save each character as its own text file, using an editor like Wordpad. Then in PHP, use `$char = file_get_contents('path/to/file.txt')` to retrieve the character? – BeetleJuice Jul 17 '16 at 07:07
I think its some apache configuration problem... I tried setting default charset, tried to read from another file, still incorrect :/ – Boy Jul 17 '16 at 07:08
You were right, I put each char as separate file, and it works now, lol – Boy Jul 17 '16 at 07:16

Two different special characters are equal

1 Answers1