This should be obvious, but I'm having trouble.
I want to replace several characters (dashes, spaces, underscores) with an empty string, but I've got something wrong.
This code: $tmp = preg_replace('/[ -_]/', '', 'filename-1055');
...returns this: "filename"
...when I'm expecting this: "filename1055"
Why the truncation?
Try str_replace instead:
$tmp = str_replace(array("-", "_", " "), "", 'filename-1055');
Unless there is a particular reason you are using preg_replace.
In a character class, dash - is the range operator, so your class [ -_] means any character in the range (space) to _.
You have two possibilities:
1- move the dash in the first or last position in the character class: [- _] or [ _-]
2- or escape it: [ \-_]
Try this way, DEMO
$re = "/([-\\s_])/";
$str = "filename-1055\n";
$subst = "";
$result = preg_replace($re, $subst, $str, 1);
Its because you did not escape - (range operator inside []) with \-. Correct code would be:
$tmp = preg_replace('/[ \-_]/', '', 'filename-1055');
Related
I want to write a PHP function that keeps only a-z (keeps all letters as lowercase) 0-9 and "-", and replace spaces with "-".
Here is what I have so far:
...
$s = strtolower($s);
$s = str_replace(' ', '-', $s);
$s = preg_replace("/[^a-z0-9]\-/", "", $s);
But I noticed that it keeps "?" (question marks) and I'm hoping that it doesn't keep other characters that I haven't noticed.
How could I correct it to obtain the expected result?
(I'm not super comfortable with regular expressions, especially when switching languages/tools.)
$s = strtolower($s);
$s = str_replace(' ', '-', $s);
$s = preg_replace("/[^a-z0-9\-]+/", "", $s);
You did not have the \- in the [] brackets.
It also seems you can use - instead of \-, both worked for me.
You need to add multiplier of the searched characters.
In this case, I used +.
The plus sign indicates one or more occurrences of the preceding element.
I have the following string:
$thetextstring = "jjfnj 948"
At the end I want to have:
echo $thetextstring; // should print jjf-nj948
So basically what am trying to do is to join the separated string then separate the first 3 letters with a -.
So far I have
$string = trim(preg_replace('/s+/', ' ', $thetextstring));
$result = explode(" ", $thetextstring);
$newstring = implode('', $result);
print_r($newstring);
I have been able to join the words, but how do I add the separator after the first 3 letters?
Use a regex with preg_replace function, this would be a one-liner:
^.{3}\K([^\s]*) *
Breakdown:
^ # Assert start of string
.{3} # Match 3 characters
\K # Reset match
([^\s]*) * # Capture everything up to space character(s) then try to match them
PHP code:
echo preg_replace('~^.{3}\K([^\s]*) *~', '-$1', 'jjfnj 948');
PHP live demo
Without knowing more about how your strings can vary, this is working solution for your task:
Pattern:
~([a-z]{2}) ~ // 2 letters (contained in capture group1) followed by a space
Replace:
-$1
Demo Link
Code: (Demo)
$thetextstring = "jjfnj 948";
echo preg_replace('~([a-z]{2}) ~','-$1',$thetextstring);
Output:
jjf-nj948
Note this pattern can easily be expanded to include characters beyond lowercase letters that precede the space. ~(\S{2}) ~
You can use str_replace to remove the unwanted space:
$newString = str_replace(' ', '', $thetextstring);
$newString:
jjfnj948
And then preg_replace to put in the dash:
$final = preg_replace('/^([a-z]{3})/', '\1-', $newString);
The meaning of this regex instruction is:
from the beginning of the line: ^
capture three a-z characters: ([a-z]{3})
replace this match with itself followed by a dash: \1-
$final:
jjf-nj948
$thetextstring = "jjfnj 948";
// replace all spaces with nothing
$thetextstring = str_replace(" ", "", $thetextstring);
// insert a dash after the third character
$thetextstring = substr_replace($thetextstring, "-", 3, 0);
echo $thetextstring;
This gives the requested jjf-nj948
You proceeding is correct. For the last step, which consists in inserting a - after the third character, you can use the substr_replace function as follows:
$thetextstring = 'jjfnj 948';
$string = trim(preg_replace('/\s+/', ' ', $thetextstring));
$result = explode(' ', $thetextstring);
$newstring = substr_replace(implode('', $result), '-', 3, false);
If you are confident enough that your string will always have the same format (characters followed by a whitespace followed by numbers), you can also reduce your computations and simplify your code as follows:
$thetextstring = 'jjfnj 948';
$newstring = substr_replace(str_replace(' ', '', $thetextstring), '-', 3, false);
Visit this link for a working demo.
Oldschool without regex
$test = "jjfnj 948";
$test = str_replace(" ", "", $test); // strip all spaces from string
echo substr($test, 0, 3)."-".substr($test, 3); // isolate first three chars, add hyphen, and concat all characters after the first three
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'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.
How can I remove the remaining part of a string after certain characters like ?, #, &, %, = in PHP? Any ideas? I tried preg_replace(), but I couldn't figure it out.
Update, just realized I read it wrong. You're looking for stuff before, not after. Updated code:
$test_string = 'remember?forget';
preg_match('/([^?#&%=]+)/', $test_string, $matches);
$part_before_char = $matches[1];
After run, $part_before_char = 'remember'
This should work:
$str = "Hello World#somesuffixstr";
preg_match("/^(.*?[?#&%=]).*/", $str, $str);
echo $str[1];
// Should output "Hello World#"
About the regex pattern:
It searches for beginning of string (^), then for any character 0 or more times (which is group #1), then such a symbol like & or %, then any character zero or more times. It replaces the string with the characters matched in group #1.
$str = 'mystring#deletedpartofstring';
$str = preg_replace('/[?#&%=].+/', '', $str);