I just stuck at this and cannot find solution.
I would like to try to transform a string to lower case using preg_replace.
I just cannot create the right regex.
The reason is that normal strtolower does not support unicode characters.
I know that I could use mb_strtolower but this function seems to be quite slow and beside them not everyone has MB support.
Any clue?
Regards,
Radek
EDIT: Ok, thanks alot for your help guys. I think my approach was not quite correct.
I think it would be much better to use this: How do I detect non-ASCII characters in a string? and then respectively use either the strtolower or mb_strtolower if available.
Regex is not able to change characters by itself, it can only change their order and/or add additional characters/delete some of them.
There is preg_replace_callback or /e flag, but they can manipulate only with known functions, and therefore can't do better than strtolower.
If you can't rely on existense of mb_strolower function, you will have to implement it yourself.
You shouldn't use a preg_replace for this because preg_replace is used to match a certain pattern and replace it with something else. Wat you want is to replace every single uppercase character with a lowercase one, so no need to match a pattern.
mb_strtolower would be the way to go, and if you don't have the mb_ functions you'll have to write a function yourself using a lot of str_replace's...
Related
I have some strings containing characters such as \x{1f601} which I want to replace with some text.
When I do this using preg_replace, it would be something like:
preg_replace('/\x{1f601}/u', '######', $str)
However, this doesn't seem to work with str_replace:
str_replace("\x{1f601}", '######', $str)
How can I make such replacements work with str_replace?
preg_replace is a Regex parser/replacer, which is a Perl Regular expression engine, but str_replace is NOT and replaces things with a plaintext method
The Preg_replace you have got can be seen here in regex101, stating that:
matches the character đ with position 0x1f601 (128513 decimal or 373001 octal) in the character set
But this could be transferable to a non-regex find and replace,by copy and pasting that face smiley symbol into the str_replace directly.
$str = str_replace("đ", '######', $str)
Or, by reading deceze's comment which gives you a clean, small solution.
Additional:
You are using a character set that is non-standard so it may be useful for you to explore Mb_Str_replace (gitHub) which is an accompanyment (but not directly from) the mb_string collection of PHP functions.
Finally:
Why do you need to do string replace whe you are already doing regex preg_replace? Also please read the manual which states all of this fairly clearly.
I am no PHP expert. I am looking for the PHP equivalent of isLetter() in Java, but I can't find it. Does it exist?
I need to extract letters from a given string and make them lower case, for example: "Ap.ér4i5T i6f;" should give "apéritif'. So, yes, there are accentuated characters in my strings.
ctype_alpha().
In addition to regex / preg_replace, you can also use strtoupper($string) and strtolower($string), if you need to universally upper-case a string. As Konrad mentioned, preg_replace is probably your best bet though.
http://php.net/manual/en/function.strtoupper.php
http://www.php.net/manual/en/function.strtolower.php
In PHP (and in Java) you wouldnât use isLetter to implement it, youâd rather replace all characters that arenât letters using a regular expression:
echo preg_replace('/\P{L}/', '', input);
Loop up the documentation of preg_replace and the regex pattern syntax desciption, in particular the relevant Unicode character classes.
You could probably use the php-slugs source code, with appropriate modifications.
I'm looking for a multi-byte function to replace preg_match_all(). I need one that will give me an array of matched strings, like the $matches argument from preg_match(). The function mb_ereg_match() doesn't seem to do it -- it only gives me a boolean indicating if there were any matches.
Looking at the mb_* functions page, I don't offhand see anythng that replaces the functionality of preg_match(). What do I use?
Edit I'm an idiot. I originally posted this question asking for a replacement for preg_match, which of course is ereg_match. However both those only return the first result. What I wanted was a replacement for preg_match_all, which returns all match texts. But anyways, the u modifier works in my case for preg_match_all, as hakre pointed out.
Have you taken a look into mb_ereg?
Additionally, you can pass an UTF-8 encoded string into preg_match using the u modifier, which might be the kind of multi-byte support you need. The other option is to encode into UTF-8 and then encode the results back.
See as well an answer to a related question: Are the PHP preg_functions multibyte safe?
PHP: preg_grep manual
$matches = preg_grep('/(needles|to|find)/u', $inputArray);
Returns an array indexed using the keys from the input array.
Note the /u modifier which enables multibyte support.
Hope it helps others.
after 10 years with php i still S*** in regex , could you please help me converting this
$x_ary=split('&x=',$url);
to the preg_split equivalent ?
Thank you
In most cases you just need to add delimiters:
preg_split('/&x=/',$url)
/ are fine if you do not need them as part of the pattern. And none of the other symbols are meta characters, so don't need escaping.
Take note that in your case you could just use explode instead, since you don't need a regex.
im new to regular expressions in php.
I have some data in which some of the values are stored as zero(0).What i want to do is to replace them with '-'. I dont know which value will get zero as my database table gets updated daily thats why i have to place that replace thing on all the data.
$r_val=preg_replace('/(0)/','-',$r_val);
The code im using is replacing all the zeroes that it finds for eg. it is even replacing zero from 104.67,giving the output 1-4.56 which is wrong. i want that data where value is exact zero that must be replaced by '-' not every zero that it encounter.
Can anyone please help!!
Example of the values that $r_val is having :-
10.31,
391.05,
113393,
15.31,
1000 etc.
This depends alot on how your data is formatted inside $r_val, but a good place to start would be to try:
$r_val = preg_replace('/(?<!\.)\b0\b(?!\.)/', '-', $r_val);
Where \b is a 0-length character representing the start or end of a 'word'.
Strange as it may sound, but the Perl regex documentation is actually really good for explaining the regex part of the preg_* functions, since Perl is where the functionality is actually implemented.
Again, it would be more than helpful if you could supply an example of what the $r_val string really looks like.
Note that \b matches at word boundaries, which would also turn a string like "0.75" into "-.75". Not a desirable result, I guess.
Whilst the other answer does work, it seems overly complex to me. I think you need only to use the ^ and $ chars either side of 0.
$r_val = preg_replace('/^0+$/', '-', $r_val);
^ indicates the regex should match from the beginning of the line.
$ indicates the regex should match to the end of the line.
+ means match this pattern 1 or more times
I altered the minus sign to it's html code equivalent too. Paranoid, yes, but we are dealing with numbers after all, so I though throwing a raw minus sign in there might not be the best idea.
Why not just do this?
if ( $r_val == 0 )
$r_val = '-';
You do not need to use a regex for this. In fact, I'd advise against doing so for performance reasons. The operation above is approximately 20x faster than the regex solution.
Also, the PHP manual advises against using regexes for simple replacements:
If you don't need fancy replacing rules (like regular expressions), you should always use this function instead of ereg_replace() or preg_replace().
http://us.php.net/manual/en/function.str-replace.php
Hope that helps!