Match a string using some regular expression - php

I've a string that looks like this:
089 / 23249841noch not deposited
and I want to extract the following portion from the string:
089 / 23249841
How can I do this using PHP and regular expressions?

Assuming you want to match everything before the first letter,
preg_match("/(^[^a-z]+)/i", "089 / 23249841noch not deposited", $match)
$match would then contain,
Array
(
[0] => 089 / 23249841
[1] => 089 / 23249841
)

With only one example, it's a little tricky to write a proper regex for that. However, this one should work:
[0-9 /]+
Or, in full PHP code:
$str = '089 / 23249841noch not deposited';
$matches = array();
if (preg_match('[0-9 /]+', $str, $matches)) {
var_dump($matches);
}

Related

Find all words/string in an expression

Lets say I have expression like
$string = ( score + total-score - total-min_score) / papoy
I want to able to extract those ALL words/term into an array ( words with/without dash and underscore )
I tried like (I'm not so good with regex)
preg_match("(\w+-_)",$string,$matches);
But it only return me the first match. How could I get all matches?
You need to use preg_match_all function.
preg_match_all('~[\w-]+~',$string,$matches);
OR
preg_match_all('~\w+(?:-\w+)*~', $string, $matches);
DEMO

Manipulating string using PHP

In PHP, I have strings like so:
$string = "This is a 123 test (your) string (for example 1234) to test.";
From that string, I'd like to get the words inside the () with the numbers. I've tried using explode but since I have 2 word/group of strings enclosed in the parentheses, I end up getting (your) instead of (for example 1234). I've also used substr like so:
substr($string, -20)
This works most of the time but the problem with this is, there are instances that the string is shorter so it ends up getting even the unwanted string. I've also tried using regular expression in which I set something like so:
/[^for]/
but that did not work either. The string I want to get always starts with "for" but the length varies. How do I manipulate php so that I can get only the string enclosed inside the parentheses that starts with the word for?
I might use preg_match() in this case.
preg_match("#\((for.*?)\)#",$string,$matches);
Any matches found would be stored in $matches.
Use the following regular expression:
(\(for.*?\))
It will capture patterns like:
(for)
(foremost)
(for example)
(for 1)
(for: 1000)
A sample PHP code:
$pattern = '/(\(for.*?\))/';
$result = preg_match_all(
$pattern,
" text (for example 1000) words (for: 20) other words",
$matches
);
if ( $result > 0 ) {
print_r( $matches );
}
Above print_r( $matches ) result:
Array
(
[0] => Array
(
[0] => (for example 1000)
[1] => (for: 20)
)
[1] => Array
(
[0] => (for example 1000)
[1] => (for: 20)
)
)
Use preg_match for regular expression
$matches = array();
$pattern = '/^for/i';
preg_match($pattern,$string,$matches);
pirnt_r($matches);
If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that matched the full pattern, $matches[1] will have the text that matched the first captured parenthesized subpattern, and so on.
$matches = array();
preg_match("/(\(for[\w\d\s]+\))/i",$string,$matches);
var_dump($matches);

Split string depending on the existence of a leading character

In PHP, I need to split a string by ":" characters without a leading "*".
This is what using explode() does:
$string = "1*:2:3*:4";
explode(":", $string);
output: array("1*", "2", "3*", "4")
However the output I need is:
output: array("1*:2", "3*:4")
How would I achieve the desired output?
You're probably looking for preg_match_all() rather than explode(), as you are attempting a more complex split than explode() itself can handle. preg_match_all() will allow you to gather all of the parts of a string that match a specific pattern, expressed using a regular expression. The pattern you are looking for is something along the lines of:
anything except : followed by *: followed by anything but :
So, try this instead:
preg_match_all('/[^:]+\*:[^:]+/', $string, $matches);
print_r($matches);
Which will output something like:
Array
(
[0] => Array
(
[0] => 1*:2
[1] => 3*:4
)
)
Which you should be able to use in much the same way that you would use the results of explode() even if there is the added dimension in the array (it divides the matches into 'groups', and all your results match against the whole expression or the first (0th) group).
$str = '1*:2:3*:4';
$res = preg_split('~(?<!\*):~',$str);
print_r($res);
will output
Array
(
[0] => 1*:2
[1] => 3*:4
)
The pattern basically says:
split by [a colon that is not lead by an asterisk]

Get all occurrences of words between curly brackets

I have a text like:
This is a {demo} phrase made for {test}
I need to get
demo
test
Note: My text can have more than one block of {}, not always two. Example:
This is a {demo} phrase made for {test} written in {English}
I used this expression /{([^}]*)}/ with preg_match but it returns only the first word, not all words inside the text.
Use preg_match_all instead:
preg_match_all($pattern, $input, $matches);
It's much the same as preg_match, with the following stipulations:
Searches subject for all matches to the regular expression given in
pattern and puts them in matches in the order specified by flags.
After the first match is found, the subsequent searches are continued
on from end of the last match.
Your expression is correct, but you should be using preg_match_all() instead to retrieve all matches. Here's a working example of what that would look like:
$s = 'This is a {demo} phrase made for {test}';
if (preg_match_all('/{([^}]*)}/', $s, $matches)) {
echo join("\n", $matches[1]);
}
To also capture the positions of each match, you can pass PREG_OFFSET_CAPTURE as the fourth parameter to preg_match_all. To use that, you can use the following example:
if (preg_match_all('/{([^}]*)}/', $s, $matches, PREG_OFFSET_CAPTURE)) {
foreach ($matches[1] as $match) {
echo "{$match[0]} occurs at position {$match[1]}\n";
}
}
As the { and } are part of regex matching syntax, you need to escape these characters:
<?php
$text = <<<EOD
this {is} some text {from}
which I {may} want to {extract}
some words {between} brackets.
EOD;
preg_match_all("!\{(\w+)\}!", $text, $matches);
print_r($matches);
?>
produces
Array
(
[0] => Array
(
[0] => {is}
[1] => {from}
[2] => {may}
[3] => {extract}
[4] => {between}
)
... etc ...
)
This example may be helpful to understand the use of curly brackets in regexes:
<?php
$str = 'abc212def3456gh34ij';
preg_match_all("!\d{3,}!", $str, $matches);
print_r($matches);
?>
which returns:
Array
(
[0] => Array
(
[0] => 212
[1] => 3456
)
)
Note that '34' is excluded from the results because the \d{3,} requires a match of at least 3 consecutive digits.
Matching portions between pair of braces using RegEx, is less better than using Stack for this purpose. Using RegEx would be something like «quick and dirty patch», but for parsing and processing input string you have to use a stack. Visit here for the concept and here for applying the same.

Regex For Get Last URL

I have:
stackoverflow.com/.../link/Eee_666/9_uUU/66_99U
What regex for /Eee_666/9_uUU/66_99U?
Eee_666, 9_uUU, and 66_99U is a random value
How can I solve it?
As simple as that:
$link = "stackoverflow.com/.../link/Eee_666/9_uUU/66_99U";
$regex = '~link/([^/]+)/([^/]+)/([^/]+)~';
# captures anything that is not a / in three different groups
preg_match_all($regex, $link, $matches);
print_r($matches);
Be aware though that it eats up any character expect the / (including newlines), so you either want to exclude other characters as well or feed the engine only strings with your format.
See a demo on regex101.com.
You can use \K here to makei more thorough.
stackoverflow\.com/.*?/link/\K([^/\s]+)/([^/\s]+)/([^/\s]+)
See demo.
https://regex101.com/r/jC8mZ4/2
In the case you don't how the length of the String:
$string = stackoverflow.com/.../link/Eee_666/9_uUU/66_99U
$regexp = ([^\/]+$)
result:
group1 = 66_99U
be careful it may also capture the end line caracter
For this kind of requirement, it's simpler to use preg_split combined with array_slice:
$url = 'stackoverflow.com/.../link/Eee_666/9_uUU/66_99U';
$elem = array_slice(preg_split('~/~', $url), -3);
print_r($elem);
Output:
Array
(
[0] => Eee_666
[1] => 9_uUU
[2] => 66_99U
)

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