I have a string that is like this ?supercategory=1&category=14&page=2 and I have a function that removes a selected filter from within that string and then returns it.
My regular expression is preg_replace('/(category=[0-9]+)&?/', '', $queryString)
Obviously the above code matches supercategory, but I want to match category in the string, not supercategory
How do I make this possible ?
I want to mention that the position of category and supercategory in the string can be changed.
Thanks
Rather than trying to use a regexp, this is a lot simpler using PHP's built-in parse_str(), unset() the category element, then use http_build_query() to recreate the query string
$dataString = 'supercategory=1&category=14&page=2';
parse_str($dataString, $urlArguments);
if (isset($urlArguments['category'])) {
unset($urlArguments['category']);
}
$dataString = http_build_query($urlArguments);
var_dump($dataString);
Related
I'm trying to match a certain string of the url using preg_match but I need to match either one or the other string and I can't find the correct syntax.
What I'm using now is:
$is_url_en = preg_match ("/\b95\b/i", $iframeurl);
This searches for the number "95" in the url. However I also want to match "en" as well but I don't know how to use the 'or' delimiter. I've seen somewhere the following:
$is_url_en = preg_match ("/\b95\b/i|/\ben\b/i", $iframeurl);
...but it doesn't work. Any hints please?
Don't repeat the / and /i. Those delimit the regex so they should only be there once.
$is_url_en = preg_match ("/\b95\b|\ben\b/i", $iframeurl);
You could then simplify this to:
$is_url_en = preg_match ("/\b(95|en)\b/i", $iframeurl);
I am looking for a way to replace all string looking alike in entire page with their defined values
Please do not recommend me other methods of including language constants.
Strings like this :
[_HOME]
[_NEWS]
all of them are looking the same in [_*] part
Now the big issue is how to scan a HTML page and to replace the defined values .
One ways to parse the html page is to use DOMDocument and then pre_replace() it
but my main problem is writing a pattern for the replacement
$pattern = "/[_i]/";
$replacement= custom_lang("/i/");
$doc = new DOMDocument();
$htmlPage = $doc->loadHTML($html);
preg_replace($pattern, $replacement, $htmlPage);
In RegEx, [] are operators, so if you use them you need to escape them.
Other problem with your expression is _* which will match Zero or more _. You need to replace it with some meaningful match, Like, _.* which will match _ and any other characters after that. SO your full expression becomes,
/\[_.*?\]/
Hey, why an ?, you might be tempted to ask: The reason being that it performs a non-greedy match. Like,
[_foo] [_bar] is the query string then a greedy match shall return one match and give you the whole of it because your expression is fully valid for the string but a non-greedy match will get you two seperate matches. (More information)
You might be better-off in being more constrictive, by having an _ followed by Capital letters. Like,
/\[_[A-Z]+\]/
Update: Using the matched strings and replacing them. To do so we use the concept called back-refrencing.
Consider modifying the above expression, enclosing the string in parentheses, like, /\[_([A-Z]+)\]/
Now in preg-replace arguments we can use the expression in parentheses by back-referencing them with $1. So what you can use is,
preg_replce("/\[_([A-Z]+)\]/e", "my_wonderful_replacer('$1')", $html);
Note: We needed the e modifier to treat the second parameter as PHP code. (More information)
If you know the full keyword you are trying to replace (e.g. [_HOME]), then you can just use str_replace() to replace all instances.
No need to make things like this more complex by introducing regex.
I have the following HTML statement
[otsection]Wallpapers[/otsection]
WALLPAPERS GO HERE
[otsection]Videos[/otsection]
VIDEOS GO HERE
What I am trying to do is replace the [otsection] tags with an html div. The catch is I want to increment the id of the div from 1->2->3, etc..
So for example, the above statement should be translated to
<div class="otsection" id="1">Wallpapers</div>
WALLPAPERS GO HERE
<div class="otsection" id="2">Videos</div>
VIDEOS GO HERE
As far as I can research, the best way to do this is via a preg_replace_callback to increment the id variable between each replacement. But after 1 hour of working on this, I just cant get it working.
Any assistance with this would be much appreciated!
Use the following:
$out = preg_replace_callback(
"(\[otsection\](.*?)\[/otsection\])is",
function($m) {
static $id = 0;
$id++;
return "<div class=\"otsection\" id=\"ots".$id."\">".$m[1]."</div>";
},
$in);
In particular, note that I used a static variable. This variable persists across calls to the function, meaning that it will be incremented every time the function is called, which happens for each match.
Also, note that I prepended ots to the ID. Element IDs should not start with numbers.
For PHP before 5.3:
$out = preg_replace_callback(
"(\[otsection\](.*?)\[/otsection\])is",
create_function('$m','
static $id = 0;
$id++;
return "<div class=\"otsection\" id=\"ots".$id."\">".$m[1]."</div>";
'),
$in);
Note: The following is intended to be a general answer and does not attempt to solve the OP's specific problem as it has already been addressed before.
What is preg_replace_callback()?
This function is used to perform a regular expression search-and-replace. It is similar to str_replace(), but instead of plain strings, it searches for a user-defined regex pattern, and then applies the callback function on the matched items. The function returns the modified string if matches are found, unmodified string otherwise.
When should I use it?
preg_replace_callback() is very similar to preg_replace() - the only difference is that instead of specifying a replacement string for the second parameter, you specify a callback function.
Use preg_replace() when you want to do a simple regex search and replace. Use preg_replace_callback() when you want to do more than just replace. See the example below for understanding how it works.
How to use it?
Here's an example to illustrate the usage of the function. Here, we are trying to convert a date string from YYYY-MM-DD format to DD-MM-YYYY.
// our date string
$string = '2014-02-22';
// search pattern
$pattern = '~(\d{4})-(\d{2})-(\d{2})~';
// the function call
$result = preg_replace_callback($pattern, 'callback', $string);
// the callback function
function callback ($matches) {
print_r($matches);
return $matches[3].'-'.$matches[2].'-'.$matches[1];
}
echo $result;
Here, our regular expression pattern searches for a date string of the format NNNN-NN-NN where N could be a digit ranging from 0 - 9 (\d is a shorthand representation for the character class [0-9]). The callback function will be called and passed an array of matched elements in the given string.
The final result will be:
22-02-2014
Note: The above example is for illustration purposes only. You should not use to parse dates. Use DateTime::createFromFormat() and DateTime::format() instead. This question has more details.
I have a string like this: Hello #"user name". Where are you from, #"user name"?
I need to get the string between the " statements (user name), but I don't know how to do it.
I tried something like this /#("(.*)"|(.[^ ]*))\s*/ but it works wrong
First off, one possible regular expression that grabs the data you need is #"(.+?)", which matches any data within quotes preceded by #, and captures the data inside. Now that you've added the regex you've tried, I'm betting that the issue is that your expression is greedy: the regex engine tries to grab the longest match possible, so returns all of #"user name". Where are you from, #"user name". Adding the ? makes the expression lazy, so it will grab the shorter match.
Since you're interested in the content inside, I'm guessing that your final goal is to replace those strings with various types of user data dynamically, so one approach would be preg_replace_callback:
function user_data($matches) {
$key = $matches[1];
// return the user data for a $key like "user name"
}
$output = preg_replace_callback('/#"(.+?)"/', 'user_data', $input);
try looking at this: http://www.php.net/manual/en/function.strstr.php you might need to explode the white space after and get the first item from the array as well.
If there is only one #"..." per string, something like this should work
$matches = array();
preg_match("/#\"(.+?)\"/i", $inputstring, $matches);
echo($matches[1]);
Try this, if its not working, just escape " in pattern
/\#\"e\;([\w\s]{0,})\"e\;/
In PHP is there an equivalent to preg_match that does not require the use of regex? There is str_replace() for preg_replace. Is there something for preg_match.
*update * I am only looking to replace a known string with another. Using regex just seems like overkill.
I have the string "This is a [test1], and not a [test2]" and I want to match them with "[test1]" and "[test2]".
If you mean find a string within another string without using regex, you can use strpos
if (strpos('hello today', 'hello') !== false) {
// string found
}
Since I am not sure what result you are looking for I can't say if this is exactly what you are looking for.
You can use strpos to see if an occurrence of one string is in another.
To answer your question there is some function of PHP without regex
Do not use preg_match() if you only
want to check if one string is
contained in another string. Use
strpos() or strstr() instead as they
will be faster.
But they can not replace preg_match completely at all
First, str_replace() is not replacement for preg_replace(). Function str_replace() replaces all occurrences of the search string with the replacement string, preg_replace() replaces content selected by regular expressions (that's not same thing).
A lot of things require regex (and that's good) so you can't simply replace it with single PHP function.
Most developers use preg_match because they want to use the matches (the third parameter which will get set by the function).
I can not think of a function that will return or set the same information, as done with matches.
If however, you are using preg_match without regex then you might not care as much about the matches.
If you are using preg_match to see if there is a "match" and just that then I'd suggest using strpos instead, since it is much more efficient at seeing if one string is found in another.