Can you please help assemble a regex to be used in preg_split which will split a string on it's first word - case insensitive (up until the first space).
This should work
$result = preg_split('/\s/', trim($subject));
$firstword = $result[0]
If sentence has space as word separators you can do:
list($firstWord) = explode(' ',trim($input));
If you just need to split up until the first space character, your regex is essentially just a space character:
$output = preg_split('/ /', 'My name is Mansoor', 2);
echo $output[0]; // Will return 'My';
echo $output[1]; // will return 'name is Mansoor';
If you only need the first word, make sure you pass the optional argument (the 2) to specify that you want only two results in your $output array -- the first word, and the rest of the sentence. Otherwise, you'll spend time parsing text that you don't care about.
Related
I'm trying to replace any occurrences when you find a single letter followed by a single number in a string.
$word = 'AB001J1'; //or ZR010F2 or ZQ10B5
echo str_replace('/^(?=.*\pL)(?=.*\p{Nd})/', '', $word);
Trying to get the result AB001 //or ZR010 or ZQ10
A regex splitting approach works well here:
$word = 'AB001J1';
$output = preg_split("/(?<=[0-9])(?=[A-Z])/", $word, 2)[0];
echo $output; // AB001
The above strategy is to split the input string at any point in between a digit and uppercase letter (in that order). This separates the various terms, and we retain only the first one.
For example, if I want to get rid of the repeating numeric suffix from the end of an expression like this:
some_text_here_1
Or like this:
some_text_here_1_5
and I want finally receive something like this:
some_text_here
What's the best and flexible solution?
$newString = preg_replace("/_?\d+$/","",$oldString);
It is using regex to match an optional underscore (_?) followed by one or more digits (\d+), but only if they are the last characters in the string ($) and replacing them with the empty string.
To capture unlimited _ numbers, just wrap the whole regex (except the $) in a capture group and put a + after it:
$newString = preg_replace("/(_?\d+)+$/","",$oldString);
If you only want to remove a numberic suffix if it is after an underscore (e.g. you want some_text_here14 to not be changed, but some_text_here_14 to be changed), then it should be:
$newString = preg_replace("/(_\d+)+$/","",$oldString);
Updated to fix more than one suffix
Strrpos is far better than regex on such a simple string problem.
$str = "some_text_here_13_15";
While(is_numeric(substr($str, strrpos($str, "_")+1))){
$str = substr($str,0 , strrpos($str, "_"));
}
Echo $str;
Strrpos finds the last "_" in str and if it's numeric remove it.
https://3v4l.org/OTdb9
Just to give you an idea of what I mean with regex not being a good solution on this here is the performance.
Regex:
https://3v4l.org/Tu8o2/perf#output
0.027 seconds for 100 runs.
My code with added numeric check:
https://3v4l.org/dkAqA/perf#output
0.003 seconds for 100 runs.
This new code performs even better than before oddly enough, regex is very slow. Trust me on that
You be the judge on what is best.
First you'll want to do a preg_replace() in order to remove all digits by using the regex /\d+/. Then you'll also want to trim any underscores from the right using rtrim(), providing _ as the second parameter.
I've combined the two in the following example:
$string = "some_text_here_1";
echo rtrim(preg_replace('/\d+/', '', $string), '_'); // some_text_here
I've also created an example of this at 3v4l here.
Hope this helps! :)
$reg = '#_\d+$#';
$replace = '';
echo preg_replace($reg, $replace, $string);
This would do
abc_def_ghi_123 > abc_def_ghi
abc_def_1 > abc_def
abc_def_ghi > abc_def_ghi
abd_def_ > abc_def_
abc_123_def > abd_123_def
in case of abd_def_123_345 > abc_def
one could change the line
$reg = '#(?:_\d+)+$#';
Here is my concern,
I have a string and I need to extract chraracters two by two.
$str = "abcdef" should return array('ab', 'bc', 'cd', 'de', 'ef'). I want to use preg_match_all instead of loops. Here is the pattern I am using.
$str = "abcdef";
preg_match_all('/[\w]{2}/', $str);
The thing is, it returns Array('ab', 'cd', 'ef'). It misses 'bc' and 'de'.
I have the same problem if I want to extract a certain number of words
$str = "ab cd ef gh ij";
preg_match_all('/([\w]+ ){2}/', $str); // returns array('ab cd', 'ef gh'), I'm also missing the last part
What am I missing? Or is it simply not possible to do so with preg_match_all?
For the first problem, what you want to do is match overlapping string, and this requires zero-width (not consuming text) look-around to grab the character:
/(?=(\w{2}))/
The regex above will capture the match in the first capturing group.
DEMO
For the second problem, it seems that you also want overlapping string. Using the same trick:
/(?=(\b\w+ \w+\b))/
Note that \b is added to check the boundary of the word. Since the match does not consume text, the next match will be attempted at the next index (which is in the middle of the first word), instead of at the end of the 2nd word. We don't want to capture from middle of a word, so we need the boundary check.
Note that \b's definition is based on \w, so if you ever change the definition of a word, you need to emulate the word boundary with look-ahead and look-behind with the corresponding character set.
DEMO
In case if you need a Non-Regex solution, Try this...
<?php
$str = "abcdef";
$len = strlen($str);
$arr = array();
for($count = 0; $count < ($len - 1); $count++)
{
$arr[] = $str[$count].$str[$count+1];
}
print_r($arr);
?>
See Codepad.
Here is my problem:
Using preg_replace('#\b(word)\b#','****',$text);
Where in text I have word\word and word, the preg_replace above replaces both word\word and word so my resulting string is ***\word and ***.
I want my string to look like : word\word and ***.
Is this possible? What am I doing wrong???
LATER EDIT
I have an array with urls, I foreach that array and preg_replace the text where url is found, but it's not working.
For instance, I have http://www.link.com and http://www.link.com/something
If I have http://www.link.com it also replaces http://www.link.com/something.
You are effectively specifying that you don't want certain characters to count as word boundary. Therefore you need to specify the "boundaries" yourself, something like this:
preg_replace('#(^|[^\w\\])(word)([^\w\\]|$)#','**',$text);
What this does is searches for the word surrounded by line boundaries or non-word characters except the back slash \. Therefore it will match .word, but not .word\ and not `\word. If you need to exclude other characters from matching, just add them inside the brackets.
You could just use str_replace("word\word", "word\word and"), I dont really see why you would need to use a preg_replace in your case given above.
Here is a simple solution that doesn't use a regex. It will ONLY replace single occurances of 'word' where it is a lone word.
<?php
$text = "word\word word cat dog";
$new_text = "";
$words = explode(" ",$text); // split the string into seperate 'words'
$inc = 0; // loop counter
foreach($words as $word){
if($word == "word"){ // if the current word in the array of words matches the criteria, replace it
$words[$inc] = "***";
}
$new_text.= $words[$inc]." ";
$inc ++;
}
echo $new_text; // gives 'word\word *** cat dog'
?>
I found this solution on stackoverflow for getting the first word from a sentence.
$myvalue = 'Test me more';
$arr = explode(' ',trim($myvalue));
echo $arr[0]; // will print Test
However, this case takes ' ' (a space) as the divider. Does anyone know how to get the first word from a string if you do not know what the divider is? It can be ' ' (space), '.' (full stop), '.' (or comma). Basically, how do you take anything that is a letter from a string up to the point where there is no letter?
E.g.:
'House, rest of sentence here' would give 'House'
'House.' would also give 'House'
'House thing' would also give 'House'
Thanks!
There is a string function (strtok) which can be used to split a string into smaller strings (tokens) based on some separator(s). For the purposes of this thread, the first word (defined as anything before the first space character) of Test me more can be obtained by tokenizing the string on the space character.
<?php
$value = "Test me more";
echo strtok($value, " "); // Test
?>
For more details and examples, see the strtok PHP manual page.
preg_split is what you're looking for.
$str = "bla1 bla2,bla3";
$words = preg_split("/[\s,]+/", $str);
This snippet splits the $str by space, \t, comma, \n.
Use the preg_match() function with a regular expression:
if (preg_match('/^\w*/', 'Your text here', $matches) > 0) {
echo $matches[0]; // $matches[0] will contain the first word of your sentence
} else {
// no match found
}