I have a problem in splitting a string using regex.
I have searched about regex to split string on uppercase word, but what I need is to split string like in the following example.
Having this example data:
This is First SentenceThis is Second Sentence
... the string should be split like this:
This is First Sentence
This is Second Sentence
Anyone know the solution for this?
You can use the \K token combined with a lookahead assertion.
$str = 'This is First SentenceThis is Second Sentence';
$results = preg_split('~[a-z]\K(?=[A-Z])~', $str);
print_r($results);
Or utilize both look-behind and lookahead assertions:
$results = preg_split('~(?<=[a-z])(?=[A-Z])~', $str);
Output
Array
(
[0] => This is First Sentence
[1] => This is Second Sentence
)
Related
I have seen some regex examples where the string is "Test string: Group1Group2", and using preg_match_all(), matching for patterns of text that exists inside the tags.
However, what I am trying to do is a bit different, where my string is something like this:
"some t3xt../s8fo=123,sij(variable1=123,variable2=743,variable3=535)"
What I want to do is match the sections such as 'variable=123' that exist inside the parenthesis.
What I have so far is this:
if( preg_match_all("/\(([^\)]*?)\)"), $string_value, $matches )
{
print_r( $matches[1] );
}
But this just captures everything that's inside the parenthesis, and doesn't match anything else.
Edit:
The desired output would be:
"variable1=123"
"variable2=743"
"variable3=535"
The output that I am getting is:
"variable1=123,variable2=743,variable3=535"
You can extract the matches you need with a single call to preg_match_all if the matches do not contain (, ) or ,:
$s = '"some t3xt../s8fo=123,sij(variable1=123,variable2=743,variable3=535)"';
if (preg_match_all('~(?:\G(?!\A),|\()\K[^,]+(?=[^()]*\))~', $s, $matches)) {
print_r($matches[0]);
}
See the regex demo and a PHP demo.
Details:
(?:\G(?!\A),|\() - either end of the preceding successful match and a comma, or a ( char
\K - match reset operator that discards all text matched so far from the current overall match memory buffer
[^,]+ - one or more chars other than a comma (use [^,]* if you expect empty matches, too)
(?=[^()]*\)) - a positive lookahead that requires zero or more chars other than ( and ) and then a ) immediately to the right of the current location.
I would do this:
preg_match("/\(([^\)]+)\)/", $string_value, $matches);
$result = explode(",", $matches[1]);
If your end result is an array of key => value then you can transform it into a query string:
preg_match("/\(([^\)]+)\)/", $string_value, $matches);
parse_str(str_replace(',', '&', $matches[1]), $result);
Which yields:
Array
(
[variable1] => 123
[variable2] => 743
[variable3] => 535
)
Or replace with a newline \n and use parse_ini_string().
I have strings with numbers-dashes sub-strings. I want to find these sub-strings and replace them after some modifications.
For example, the string is like:
This is the string number 123-45-6789-0 which contains 12-34567.
Now I want to find sub-strings of numbers-dashes (123-45-6789-0 and 12-34567) and replace them with the modified sub-strings. For example the final string would be like this:
This is the modified string number 0-6789-45-123 which contains 34567-12.
I have already tried preg_match_all(string $pattern, string $subject, array &$matches) with:
$pattern = '/-*\d+-*/';
but it gives me an array of numbers each one with a dash, like this:
$matches = [123-, 45-, 6789-, 0, 12-, 34567]
whereas, I want an array of two sub-strings, like this:
$matches = [0 => 123-45-6789-0, 1 => 12-34567]
in order to do modifications and replacements (using str_replace()), separately.
Which pattern and methods should I use for these purpose?
Thanks in advance.
You may use \d+(?:-\d+)+ regex with a preg_replace_callback` function:
$str = 'This is the string number 123-45-6789-0 which contains 12-34567.';
echo preg_replace_callback('~\d+(?:-\d+)+~', function($m) {
return implode('-', array_reverse(explode('-', $m[0]))); }
,$str);
// => This is the string number 0-6789-45-123 which contains 34567-12.
See PHP demo and the regex demo.
The \d+(?:-\d+)+ pattern matches
\d+ - 1+ digits
(?:-\d+)+ - 1 or more occurrences of - and 1+ digits sequences.
$m is a match array, $m[0] holds the match value. With explode, the string is split with -, then the array is reversed, and then joined back with implode.
I have a string like this:
page-9000,page-template,page-type,page-category-128,image-195,listing-latest,rss-latest,even-more-info,even-more-tags
I made this regex that I expect to get the whole tags with:
(?<=\,)(rss-latest|listing-latest-no-category|category-128|page-9000)(?=\,)
I want it to match all the ocurrences.
In this case:
page-9000 and rss-latest.
This regex checks whole words between commas just fine but it ignores the first and the last because it's not between commas (obviously).
I've also tried that it checks if it's between commas OR one comma at the beginning OR one comma to the end, however it would give me false positives, as it would match:
category-128
while the string contains:
page-category-128
Any help?
Try using the following pattern:
(?<=,|^)(rss-latest|listing-latest-no-category|category-128|page-9000)(?=,|$)
The only change I have made is to add boundary markers ^ and $ to the lookarounds to also match on the start and end of the input.
Script:
$input = "page-9000,page-template,page-type,page-category-128,image-195,listing-latest,rss-latest,even-more-info,even-more-tags";
preg_match_all("/(?<=,|^)(rss-latest|listing-latest-no-category|category-128|page-9000)(?=,|$)/", $input, $matches);
print_r($matches[1]);
This prints:
Array
(
[0] => page-9000
[1] => rss-latest
)
Here is a non-regex way using explode and array_intersect:
$arr1 = explode(',', 'page-9000,page-template,page-type,page-category-128,image-195,listing-latest,rss-latest,even-more-info,even-more-tags');
$arr2 = explode('|', 'rss-latest|listing-latest-no-category|category-128|page-9000');
print_r(array_intersect($arr1, $arr2));
Output:
Array
(
[0] => page-9000
[6] => rss-latest
)
The (?<=\,) and (?=,) require the presence of , on both sides of the matching pattern. You want to match also at the start/end of string, and this is where you need to either explicitly tell to match either , or start/end of string or use double-negating logic with negated character classes inside negative lookarounds.
You may use
(?<![^,])(?:rss-latest|listing-latest-no-category|category-128|page-9000)(?![^,])
See the regex demo
Here, (?<![^,]) matches the start of string position or a , and (?![^,]) matches the end of string position or ,.
Now, you do not even need a capturing group, you may get rid of its overhead using a non-capturing group, (?:...). preg_match_all won't have to allocate memory for the submatches and the resulting array will be much cleaner.
PHP demo:
$re = '/(?<![^,])(?:rss-latest|listing-latest-no-category|category-128|page-9000)(?![^,])/m';
$str = 'page-9000,page-template,page-type,page-category-128,image-195,listing-latest,rss-latest,even-more-info,even-more-tags';
if (preg_match_all($re, $str, $matches)) {
print_r($matches[0]);
}
// => Array ( [0] => page-9000 [1] => rss-latest )
I have a text in PHP stored in the variable $row. I'd like to find the position of a certain group of words and that's quite easy. What's not so easy is to make my code recognize that the word it has found is exactly the word i'm looking for or a part of a larger word. Is there a way to do it?
Example of what I'd like to obtain
CODE:
$row= "some ugly text of some kind i'd like to find in someway"
$token= "some";
$pos= -1;
$counter= substr_count($row, $token);
for ($h=0; $h<$counter; $h++) {
$pos= strpos($row, $token, $pos+1);
echo $pos.' ';
}
OUTPUT:
what I obtain:
0 17 47
what I'd like to obtain
0 17
Any hint?
Use preg_match_all() with word boundaries (\b):
$search = preg_quote($token, '/');
preg_match_all("/\b$search\b/", $row, $m, PREG_OFFSET_CAPTURE);
Here, the preg_quote() statement is used to correctly escape the user input so as to use it in our regular expression. Some characters have special meaning in regular expression language — without proper escaping, those characters will lose their "special meaning" and your regex might not work as intended.
In the preg_match_all() statement, we are supplying the following regex:
/\b$search\b/
Explanation:
/ - starting delimiter
\b - word boundary. A word boundary, in most regex dialects, is a position between a word character (\w) and a non-word character (\W).
$search - escaped search term
\b - word boundary
/ - ending delimiter
In simple English, it means: find all the occurrences of the given word some.
Note that we're also using PREG_OFFSET_CAPTURE flag here. If this flag is passed, for every occurring match the appendant string offset will also be returned. See the documentation for more information.
To obtain the results you want, you can simply loop through the $m array and extract the offsets:
$result = implode(' ', array_map(function($arr) {
return $arr[1];
}, $m[0]));
echo $result;
Output:
0 18
Demo
What you're looking for is a combination of Regex with a word boundaries pattern and the flag to return the offset (PREG_OFFSET_CAPTURE).
PREG_OFFSET_CAPTURE
If this flag is passed, for every occurring match the appendant
string offset will also be returned. Note that this changes the
value of matches into an array where every element is an array
consisting of the matched string at offset 0 and its string offset
into subject at offset 1.
$row= "some ugly text of some kind i'd like to find in someway";
$pattern= "/\bsome\b/i";
preg_match_all($pattern, $row, $matches, PREG_OFFSET_CAPTURE);
And we get something like this:
Array
(
[0] => Array
(
[0] => Array
(
[0] => some
[1] => 0
)
[1] => Array
(
[0] => some
[1] => 18
)
)
)
And just loop through the matches and extract the offset where the needle was found in the haystack.
// store the positions of the match
$offsets = array();
foreach($matches[0] as $match) {
$offsets[] = $match[1];
}
// display the offsets
echo implode(' ', $offsets);
Use preg_match():
if(preg_match("/some/", $row))
// [..]
The first argument is a regex, which can match virtually anything you want to match. But, there are dire warnings about using it to match things like HTML.
I have been using
explode(".",$mystring)
to split a paragraph into sentences. However this doen't cover sentences that have been concluded with different punctuation such as ! ? : ;
Is there a way of using an array as a delimiter instead of a single character? Alternativly is there another neat way of splitting using various punctuation?
I tried
explode(("." || "?" || "!"),$mystring)
hopefully but it didn't work...
You can use preg_split() combined with a PCRE lookahead condition to split the string after each occurance of ., ;, :, ?, !, .. while keeping the actual punctuation intact:
Code:
$subject = 'abc sdfs. def ghi; this is an.email#addre.ss! asdasdasd? abc xyz';
// split on whitespace between sentences preceded by a punctuation mark
$result = preg_split('/(?<=[.?!;:])\s+/', $subject, -1, PREG_SPLIT_NO_EMPTY);
print_r($result);
Result:
Array
(
[0] => abc sdfs.
[1] => def ghi;
[2] => this is an.email#addre.ss!
[3] => asdasdasd?
[4] => abc xyz
)
You can also add a blacklist for abbreviations (Mr., Mrs., Dr., ..) that should not be split into own sentences by inserting a negative lookbehind assertion:
$subject = 'abc sdfs. Dr. Foo said he is not a sentence; asdasdasd? abc xyz';
// split on whitespace between sentences preceded by a punctuation mark
$result = preg_split('/(?<!Mr.|Mrs.|Dr.)(?<=[.?!;:])\s+/', $subject, -1, PREG_SPLIT_NO_EMPTY);
print_r($result);
Result:
Array
(
[0] => abc sdfs.
[1] => Dr. Foo said he is not a sentence;
[2] => asdasdasd?
[3] => abc xyz
)
You can do:
preg_split('/\.|\?|!/',$mystring);
or (simpler):
preg_split('/[.?!]/',$mystring);
Assuming that you actually want the punctuations marks with the end result, have you tried:
$mystring = str_replace("?","?---",str_replace(".",".---",str_replace("!","!---",$mystring)));
$tmp = explode("---",$mystring);
Which would leave your punctuation marks in tact.
preg_split('/\s+|[.?!]/',$string);
A possible problem might be if there is an email address as it could split it onto a new line half way through.
Use preg_split and give it a regex like [\.|\?!] to split on
You can't have multiple delimiters for explode. That's what preg_split(); is for. But even then, it explodes at the delimiter, so you will get sentences returned without the punctuation marks.
You can take preg_split a step farther and flag it to return them in their own elements with PREG_SPLIT_DELIM_CAPTURE and then run some loop to implode sentence and following punctation mark in the returned array, or just use preg_match_all();:
preg_match_all('~.*?[?.!]~s', $string, $sentences);
$mylist = preg_split("/[.?!:;]/", $mystring);
You can try preg_split
$sentences = preg_split("/[.?!:;]+/", $mystring);
Please note this will remove the punctuations. If you would like to strip out leading or trailing whitespace as well
$sentences = preg_split("/[.?!:;]+\s+?/", $mystring);