I recently have played around with the use of preg_replace in PHP to specifically remove a string once.
However I have a list of numbers (345, 346 and wanting to remove ", 346" for example) and I have kept on running into the same problem how it removes the whole string and leaves it empty.
Desired results are
345, 346
Removing ", 346"
Turns to
345
And also
345, 346, 347 removing ", 346"
Turns to
345, 347
Code:
$oldpost = ", ".$_GET['id'];
$newposts = preg_replace($oldpost, "", $row['posts']);
I tried this previously and haven't found anything that seems to do a better job.
In your code, you have
$newposts = preg_replace($oldpost, "", $row['posts']);
where you are actually giving the entire string itself to be replaced. Hence, it gives you an empty string because your 2nd parameter is an empty string.
You can match the exact 346(if it's present) with an optional matching of a , and replace them with empty string. So your regex would look like
/(,?\s*346(\s|,|\b))?/
Snippet:
<?php
$oldpost = "345,346,347";
$newposts = preg_replace("/(,?\s*346(\s|,|\b))?/", "$2", $oldpost);
echo $newposts,PHP_EOL;
Demo: https://3v4l.org/MeSeK
Note that above approach works fine, but the best way to solve this problem is to explode the comma separated string and unset the location in the array where have the 346 and implode it back again.
Snippet:
<?php
$oldpost = "345,346,347";
$posts = explode(",",$oldpost);
$index = array_search(346,$posts);
if($index !== false){
unset($posts[$index]);
}
$new_post = implode(",",$posts);
echo $new_post;
Demo: https://3v4l.org/qvSEN
Note that if there are multiple occurrences of 346, you can use a simple foreach to unset them.
Documentation is here for preg_replace:
https://www.php.net/manual/en/function.preg-replace.php
Try adding a value for the "limit" parameter.
limit:
The maximum possible replacements for each pattern in each subject string. Defaults to -1 (no limit).
Related
Is there any way to do this with preg_replace or other php code?
I have a string that looks like this:
[[10],[11],[2],[3],[5],[1],[10],[15],[20],[21],[14],[16],[17],[6],[9],[4]]
I want to display like this:
[[10,11],[2,3],[5,1],[10,15],[20,21],[14,16],[17,6],[9,4]]
So I replaced the "],[" part with str_replace
$xy1 = str_replace('],[', ',', $xy1);
And now looks like this:
[[10,11,2,3,5,1,10,15,20,21,14,16,17,6,9,4]]
But I need to add an extra "]" after every second number and an extra [ after every second comma ex.:
[[10,11],[2,3],[5,1]
A couple of possibilities:
The string is valid JSON, whether it was intended to be or not, so you can decode it, chunk the resulting array and re-encode it.
$result1 = json_encode(array_chunk(array_column(json_decode($string),0),2));
If you are producing the string in your previous code via json_encode it would be much better to just use array_chunk at that time, but if it's coming from some other source you obviously can't do that.
For this specific string, it may be less cumbersome to pair the numbers with a regex.
$result2 = preg_replace('/(\d+)\D+(\d+)/', '$1,$2', $string);
Or a combination of both ways, extract all the numbers and then chunk and encode.
preg_match_all('/\d+/', $string, $numbers);
$result3 = json_encode(array_chunk($numbers[0], 2), JSON_NUMERIC_CHECK);
This might help, extract the nested array values and then group them by pairs.
$newArray = array_chunk( array_column( $array, 0 ), 2 );
i am making php array count value function i am taking values from file get content and using it in it and want to count values but due to space its not working properly Here is my codes
$data = file_get_contents('testr.txt');
preg_match_all('#mob:-(\S+)-#',$data,$matches);
$nu=$matches[1];
$n=implode($nu,',');
$n="9024453561,9024453561,9024453561,9024453561,9024453561 ";
//in value of $n i am getting spce at end so array_count _value not working
$array = array($n);
$counts = array_count_values($array);
echo $counts['9024453561'];
Using array_map(), map over your data where your call implode like so:
$n=array_map('trim', implode($nu,','));
This will remove any white space you have in your array values.
Hope that helps,
You do not split the string into an array by array($n). Instead you get a single element containing the entire string including commas. Use trim and preg_split to get an array of values.
$n="9024453561,9024453561,9024453561,9024453561,9024453561 ";
$array = preg_split('~\\s*,\\s*~u', trim($n));
$counts = array_count_values($array);
echo $counts['9024453561'];
This also splits a string like " 123 , 456 , 789 ". \s* means zero or more whitespaces. The double slash is to escape the slash in the string literal. trim removes spaces from the begin and the end of the entire string.
There is no need to go through the implode at all, just call array_count_values on your preg_match_all result:
$data = file_get_contents('testr.txt');
preg_match_all('#mob:-(\S+)-#',$data,$matches);
$nu=$matches[1];
$counts = array_count_values($nu);
echo $counts['9024453561'];
I have following issue:
I import WKT dynamicaly from DB into WKT Wicket Javascript library. I must do some substitutions to fit the WKT correctly. Since mysql fetches WKT AsText(SHAPE) i recive several arrays e.g. POLYGON((xxxx)),POLYGON((yyyy)) and so on.
First, I had to remove all "POLYGON" doing
$str = preg_replace('/^POLYGON/', '', $WKT[1]);
and add MULTIPOLYGON before <?php
tag in the wicket. It works.
Second, I must add comma between polygons, preicisely between "))((" brackets:
$str2 = str_replace(array('((', '))'), array('((', ')),'), $str);
It works but last comma remains what "slightly" deforms my multipolygon:
MULTIPOLYGON((xxx)),((yyy)),((zzz)),
How can I remove last comma?
I would be thankful for every regex or some other solution which can solve my problem.
In any string, you can remove the last X if you are sure that no X follows. So, you can use a negative lookahead: (,)(?!.*,), as seen here and replace it with empty string.
$result = preg_replace('/(,)(?!.*,)/', '', $str)
This doesn't look at the context though, it will just remove the last comma of any string, no matter where it is.
Thank you both - your answers were right and very helpful.
The problem was not string replacement. It was more the data fetching from DB.
Mysqli_fetch_array and mysqli_fetch_assoc return stringstringsring or arrayarrayarray for 3 rows fetched. That is why all commas were replaced.
I changed to mysqli_fetch_all ,then did minor replacements for each row (as array) and implode each one as variable. After i merged them into single variable, then I could apply your solutions. It is not sofisticated solution, but if it is packed into function it'll be fine.
($WKT = mysqli_fetch_all($result)) {
$str = preg_replace('/POLYGON/', '', $WKT[0]);
$str1 = preg_replace('/POLYGON/', '', $WKT[1]);
$str2 = preg_replace('/POLYGON/', '', $WKT[2]);
$str3 = implode($str);
$str4 = implode($str1);
$str5 = implode($str2);
$str6 = $str3 . $str4 . $str5;
$str7 = preg_replace('/\)\)/', ')),', $str6);
$str8 = rtrim($str7, ",");
echo $str8;
}
I thought I had this working; however after further evaluation it seems it's not working as I would have hoped it was.
I have a query pulling back a string. The string is a comma separated list just as you see here:
(1,145,154,155,158,304)
Nothing has been added or removed.
I have a function that I thought I could use preg_match to determine if the user's id was contained within the string. However, it appears that my code is looking for any part.
preg_match('/'.$_SESSION['MyUserID'].'/',$datafs['OptFilter_1']))
using the same it would look like such
preg_match('/1/',(1,145,154,155,158,304)) I would think. After testing if my user id is 4 the current code returns true and it shouldn't. What am I doing wrong? As you can see the id length can change.
It's better to have all your IDs in an array then checking if a desired ID is existed:
<?php
$str = "(1,145,154,155,158,304)";
$str = str_replace(array("(", ")"), "", $str);
$arr = explode(',', $str);
if(in_array($_SESSION['MyUserID'], $arr))
{
// ID existed
}
As your string - In dealing with Regular Expressions, however it's not recommended here, below regex will match your ID if it's there:
preg_match("#[,(]$ID[,)]#", $str)
Explanations:
[,(] # a comma , or opening-parenthesis ( character
$ID # your ID
[,)] # a comma , or closing-parenthesis ) character
I'm trying to figure out how to convert html textarea into php array,
I've used a form with POST to deliver the query to the php script,
and the php file is getting them with the following line:
$ids = array($_POST['ids']);
Needless to say that it puts everything into one line
Array ( [0] => line1 line2 line3 line4 )
I need the final results to replace this:
$numbers = array(
"line1",
"line2",
"line3",
"line4"
);
What would be the best approach to divide and re-parse it ?
Using an explode on \n is a proper way to get new lines. keep in mind though that on some platforms the end of line is actually send by \r\n, so just exploding on \n could leave you with extra data on the end of each line.
My suggestion would be to remove the \r before exploding, so you dont have to loop through the entire array to trim the result. As a last improvement, you dont know that there actually is a $_POST['ids'], so always check it first.
<?
$input = isset($_POST['ids'])?$_POST['ids']:"";
//I dont check for empty() incase your app allows a 0 as ID.
if (strlen($input)==0) {
echo 'no input';
exit;
}
$ids = explode("\n", str_replace("\r", "", $input));
?>
I would've done the explode by Hugo like this:
$ids = explode(PHP_EOL, $input);
manual Predefined Constants
Just my two cents...
Use this
$new_array = array_values(array_filter(explode(PHP_EOL, $input)));
explode -> convert textarea to php array (that lines split by new line)
array_filter -> remove empty lines from array
array_values -> reset keys of array
If the textarea simply has line breaks per entry then I'd do something like:
$ids = nl2br($_POST['ids');
$ids = explode('<br />',$ids); //or just '<br>' depending on what nl2br uses.
Try with explode function:
$ids = $_POST['ids']; // not array($_POST['ids'])
$ids = explode(" ", $ids);
The first parameter is the delimiter which could be space, new line character \r\n, comma, colon etc. according to your string from the textarea (it's not clear from the question whether values are separated by spaces or by new lines).