I have been trying to replace a portion of a string if two of more non alphanumeric characters are found.
I have it partly working but can not replace when a underscore is in there.
This is what i am trying.
$str = "-dxs_ s";
$str = preg_replace('/\W{2,}|\_{2,}/', ' ', $str);
reults in -dxs_ s should be -dxs s.
So how do you replace if two or more non alphanumeric characters are found in a string?
Simply
$str = preg_replace('/(\W|_){2,}/', ' ', $str);
What this is doing is grouping the "non-word or underscore" part and applies the 2+ quantifier to it as a whole.
See it in action.
\W also excludes _ therefore you need your own characters class :
/[^a-zA-Z0-9]{2,}/
or
$result = preg_replace('/[^a-z\d]{2,}/i', ' ', $subject);
Related
I'm making a function that that detect and remove all trailing special characters from string. It can convert strings like :
"hello-world"
"hello-world/"
"hello-world--"
"hello-world/%--+..."
into "hello-world".
anyone knows the trick without writing a lot of codes?
Just for fun
[^a-z\s]+
Regex demo
Explanation:
[^x]: One character that is not x sample
\s: "whitespace character": space, tab, newline, carriage return, vertical tab sample
+: One or more sample
PHP:
$re = "/[^a-z\\s]+/i";
$str = "Hello world\nhello world/\nhello world--\nhellow world/%--+...";
$subst = "";
$result = preg_replace($re, $subst, $str);
try this
$string = preg_replace('/[^A-Za-z0-9\-]/', '', $string); // Removes special chars.
or escape apostraphe from string
preg_replace('/[^A-Za-z0-9\-\']/', '', $string); // escape apostraphe
You could use a regex like this, depending on your definition of "special characters":
function clean_string($input) {
return preg_replace('/\W+$/', '', $input);
}
It replaces any characters that are not a word character (\W) at the end of the string $ with nothing. \W will match [^a-zA-Z0-9_], so anything that is not a letter, digit, or underscore will get replaced. To specify which characters are special chars, use a regex like this, where you put all your special chars within the [] brackets:
function clean_string($input) {
return preg_replace('/[\/%.+-]+$/', '', $input);
}
This one is what you are looking for. :
([^\n\w\d \"]*)$
It removes anything that is not from the alphabet, a number, a space and a new line.
Just call it like this :
preg_replace('/([^\n\w\s]*)$/', '', $string);
I am trying to add a span tag to the last word of a string. It works if the string has no special characters. I can't figure out the correct regex for it.
$string = "Onun Mesajı";
echo preg_replace("~\W\w+\s*\S?$~", ' <span>' . '\\0' . '</span>', $string);
Here is the Turkish character set : ÇŞĞÜÖİçşğüöı
You need to use /u modifier to allow processing Unicode characters in the pattern and input string.
preg_replace('~\w+\s*$~u', '<span>$0</span>', $string);
^
Full PHP demo:
$string = "Onun Mesajı";
echo preg_replace("~\w+\s*$~u", '<span>$0</span>', $string);
Also, the regex you need is just \w+\s*$:
\w+ - 1 or more alphanumerics
\s* - 0 or more whitespace (trailing)
$ - end of string
Since I removed the \W from the regex, there is no need to "hardcode" the leading space in the replacement string (removed, too).
You should use the u modifier for regular expressions to set the engine into unicode mode:
<?php
$subject = "Onun äöüß Mesajı";
$pattern = '/\w+\s*?$/u';
echo preg_replace($pattern, '<span>\\0</span>', $subject);
The output is:
Onun äöüß <span>Mesajı</span>
This regex will do the trick for you, and is a lot shorter then the other solutions:
[ ](.*?$)
Here is an example of it:
$string = "Onun Mes*ÇŞĞÜÖİçşğüöıajı";
echo preg_replace('~[ ](.*?$)~', ' <span>' .'${1}'. '</span>', $string);
Will echo out:
Onun <span>Mes*ÇŞĞÜÖİçşğüöıajı</span>
The way this regex works is that we look for any characters without space in lazy mode [ ].*?.
then we add the $ identifier, so it matches from the end of the string instead.
I'm trying to remove all words of less than 3 characters from a string, specifically with RegEx.
The following doesn't work because it is looking for double spaces. I suppose I could convert all spaces to double spaces beforehand and then convert them back after, but that doesn't seem very efficient. Any ideas?
$text='an of and then some an ee halved or or whenever';
$text=preg_replace('# [a-z]{1,2} #',' ',' '.$text.' ');
echo trim($text);
Removing the Short Words
You can use this:
$replaced = preg_replace('~\b[a-z]{1,2}\b\~', '', $yourstring);
In the demo, see the substitutions at the bottom.
Explanation
\b is a word boundary that matches a position where one side is a letter, and the other side is not a letter (for instance a space character, or the beginning of the string)
[a-z]{1,2} matches one or two letters
\b another word boundary
Replace with the empty string.
Option 2: Also Remove Trailing Spaces
If you also want to remove the spaces after the words, we can add \s* at the end of the regex:
$replaced = preg_replace('~\b[a-z]{1,2}\b\s*~', '', $yourstring);
Reference
Word Boundaries
You can use the word boundary tag: \b:
Replace: \b[a-z]{1,2}\b with ''
Use this
preg_replace('/(\b.{1,2}\s)/','',$your_string);
As some solutions worked here, they had a problem with my language's "multichar characters", such as "ch". A simple explode and implode worked for me.
$maxWordLength = 3;
$string = "my super string";
$exploded = explode(" ", $string);
foreach($exploded as $key => $word) {
if(mb_strlen($word) < $maxWordLength) unset($exploded[$key]);
}
$string = implode(" ", $exploded);
echo $string;
// outputs "super string"
To me, it seems that this hack works fine with most PHP versions:
$string2 = preg_replace("/~\b[a-zA-Z0-9]{1,2}\b\~/i", "", trim($string1));
Where [a-zA-Z0-9] are the accepted Char/Number range.
I have this code which does what I want, but in four steps. I want only alphanumeric lower case letters, and space should be replaced by an underscore. I have written this function but want to learn if it's possible with one preg_replace() function call:
$str = 'qwerty!##$##$^##$Hello %#$sdsdsss';
$cityu= strtolower($str);
$id = str_replace(' ', '_', $cityu);
$outcome = preg_replace("/[^a-zA-Z0-9_]/", "", $id);
var_dump($outcome);
I want one preg_replace() to do this.
You can't use a single replacement string since you're doing two distinct operations, but preg_replace() can take arrays as arguments. This allows you to makes multiple sets of replacements in a single preg_replace() call.
$str = strtolower('qwerty!##$##$^##$Hello %#$sdsdsss');
echo preg_replace(array('/ /', '/\W/'), array('_', ''), $str);
// output: qwertyhello_sdsdsss
\W is a negated shorthand character class which is equivalent to [^A-Za-z0-9_].
Note that replacement order matters. Replacements will occur in the order they're listed, so you would get a different result in reverse order: first non-word characters would be replaced, then spaces, but the spaces will already have been removed in the first step.
echo preg_replace(array('/\W/', '/ /'), array('', '_'), $str);
// output: qwertyhellosdsdsss
I've got text from which I want to remove all characters that ARE NOT the following.
desired_characters =
0123456789!&',-./abcdefghijklmnopqrstuvwxyz\n
The last is a \n (newline) that I do want to keep.
To match all characters except the listed ones, use an inverted character set [^…]:
$chars = "0123456789!&',-./abcdefghijklmnopqrstuvwxyz\n";
$pattern = "/[^".preg_quote($chars, "/")."]/";
Here preg_quote is used to escape certain special characters so that they are interpreted as literal characters.
You could also use character ranges to express the listed characters:
$pattern = "/[^0-9!&',-.\\/a-z\n]/";
In this case it doesn’t matter if the literal - in ,-. is escaped or not. Because ,-. is interpreted as character range from , (0x2C) to . (0x2E) that already contains the - (0x2D) in between.
Then you can remove those characters that are matched with preg_replace:
$output = preg_replace($pattern, "", $str);
$string = 'This is anexample $tring! :)';
$string = preg_replace('/[^0-9!&\',\-.\/a-z\n]/', '', $string);
echo $string; // hisisanexampletring!
^ This is case sensitive, hence the capital T is removed from the string. To allow capital letters as well, $string = preg_replace('/[^0-9!&\',\-.\/A-Za-z\n]/', '', $string)