I try to split my string into an array. All strings between the calculation signs +/*-:
$keywords = preg_split("/[\s,-]*[+-*]+/", "quanity*price/2+tax");
This is what I try to achieve:
Array
(
[0] => quantity
[1] => price
[1] => tax
)
But the result is an empty string.
In the pattern you tried the second character class is not matching a digit and the hyphen should be escaped or placed at the beginning/end.
You could use a single character class instead. If you change the delimiter to other than / like ~ you don't have to escape the forward slash.
[-*\/+\d]+
Regex demo | Php demo
For example
$strings = [
"quanity*price/2+tax",
"quanity*price/2"
];
foreach ($strings as $string) {
$keywords = preg_split("~[-*/+\d]+~", $string, -1, PREG_SPLIT_NO_EMPTY);
print_r($keywords);
}
Output
Array
(
[0] => quanity
[1] => price
[2] => tax
)
Array
(
[0] => quanity
[1] => price
)
If you also want to match 0+ preceding whitespace chars, comma's:
[\s,]*[-*/+\d]+
Regex demo
This will split the string where any of these exist: +/* and create an array out of it:
$string = "quanity*price/2+tax";
$str_arr = preg_split ("/[-*\/+\d]+/", $string);
print_r($str_arr);
Posted code with your example for clarity.
Using the regex that The fourth bird recommended:
$keywords = preg_split("/[-*\/+\d]+/", "quanity*price/2+tax", -1, PREG_SPLIT_NO_EMPTY);
The PREG_SPLIT_NO_EMPTY should drop empty values (https://www.php.net//manual/en/function.preg-split.php).
Related
After instructing clients to input only
number comma number comma number
(no set length, but generally < 10), the results of their input have been, erm, unpredictable.
Given the following example input:
3,6 ,bannana,5,,*,
How could I most simply, and reliably end up with:
3,6,5
So far I am trying a combination:
$test= trim($test,","); //Remove any leading or trailing commas
$test= preg_replace('/\s+/', '', $test);; //Remove any whitespace
$test= preg_replace("/[^0-9]/", ",", $test); //Replace any non-number with a comma
But before I keep throwing things at it...is there an elegant way, probably from a regex boffin!
In a purely abstract sense this is what I'd do:
$test = array_filter(array_map('trim',explode(",",$test)),'is_numeric')
Example:
http://sandbox.onlinephpfunctions.com/code/753f4a833e8ff07cd9c7bd780708f7aafd20d01d
<?php
$str = '3,6 ,bannana,5,,*,';
$str = explode(',', $str);
$newArray = array_map(function($val){
return is_numeric(trim($val)) ? trim($val) : '';
}, $str);
print_r(array_filter($newArray)); // <-- this will give you array
echo implode(',',array_filter($newArray)); // <--- this give you string
?>
Here's an example using regex,
$string = '3,6 ,bannana,5,-6,*,';
preg_match_all('#(-?[0-9]+)#',$string,$matches);
print_r($matches);
will output
Array
(
[0] => Array
(
[0] => 3
[1] => 6
[2] => 5
[3] => -6
)
[1] => Array
(
[0] => 3
[1] => 6
[2] => 5
[3] => -6
)
)
Use $matches[0] and you should be on your way.
If you don't need negative numbers just remove the first bit in the in the regex rule.
I am trying to explode / preg_split a string so that I get an array of all the values that are enclosed in ( ). I've tried the following code but I always get an empty array, I have tried many things but I cant seem to do it right
Could anyone spot what am I missing to get my desired output?
$pattern = "/^\(.*\)$/";
$string = "(y3,x3),(r4,t4)";
$output = preg_split($pattern, $string);
print_r($output);
Current output Array ( [0] => [1] => )
Desired output Array ( [0] => "(y3,x3)," [1] => "(r4,t4)" )
With preg_split() your regex should be matching the delimiters within the string to split the string into an array. Your regex is currently matching the values, and for that, you can use preg_match_all(), like so:
$pattern = "/\(.*?\)/";
$string = "(y3,x3),(r4,t4)";
preg_match_all($pattern, $string, $output);
print_r($output[0]);
This outputs:
Array
(
[0] => (y3,x3)
[1] => (r4,t4)
)
If you want to use preg_split(), you would want to match the , between ),(, but without consuming the parenthesis, like so:
$pattern = "/(?<=\)),(?=\()/";
$string = "(y3,x3),(r4,t4)";
$output = preg_split($pattern, $string);
print_r($output);
This uses a positive lookbehind and positive lookahead to find the , between the two parenthesis groups, and split on them. It also output the same as the above.
You can use a simple regex like \B,\B to split the string and improve the performance by avoiding lookahead or lookbehind regex.
\B is a non-word boundary so it will match only the , between ) and (
Here is a working example:
http://regex101.com/r/cV7bO7/1
$pattern = "/\B,\B/";
$string = "(y3,x3),(r4,t4),(r5,t5)";
$result = preg_split($pattern, $string);
$result will contain:
Array
(
[0] => (y3,x3)
[1] => (r4,t4)
[2] => (r5,t5)
)
I want the results to be:
Cats, Felines & Cougars
Dogs
Snakes
This is the closest I can get.
$string = "Cats, Felines & Cougars,Dogs,Snakes";
$result = split(',[^ ]', $string);
print_r($result);
Which results in
Array
(
[0] => Cats, Felines & Cougars
[1] => ogs
[2] => nakes
)
You can use a negative lookahead to achieve this:
,(?!\s)
In simple English, the above regex says match all commas only if it is not followed by a space (\s).
In PHP, you can use it with preg_split(), like so:
$string = "Cats, Felines & Cougars,Dogs,Snakes";
$result = preg_split('/,(?!\s)/', $string);
print_r($result);
Output:
Array
(
[0] => Cats, Felines & Cougars
[1] => Dogs
[2] => Snakes
)
the split() function has been deprecated so I'm using preg_split instead.
Here's what you want:
$string = "Cats, Felines & Cougars,Dogs,Snakes";
$result = preg_split('/,(?! )/', $string);
print_r($result);
This uses ?! to signify that we want split on a comma only when not followed by the grouped sequence.
I linked the Perl documentation on the operator since preg_split uses Perl regular expressions:
http://perldoc.perl.org/perlre.html#Look-Around-Assertions
If you want to split by a char, but want to ignore that char in case it is escaped, use a lookbehind assertion.
In this example a string will be split by ":" but "\:" will be ignored:
<?php
$string='a:b:c\:d';
$array=preg_split('#(?<!\\\)\:#',$string);
print_r($array);
?>
Results into:
Array
(
[0] => a
[1] => b
[2] => c\:d
)
http://www.php.net//manual/en/function.preg-split.php
i have a string like {ASK(Value, Value, 'Sentence', Some_Char)} and i need to get of exploded values in (). What i am doing wrong?
preg_match_all('/\{ASK\((.*?),\)\}/', '{ASK(Value, Value, \'Sentence\', X)}', $matches);
print_r($matches);
Take out the comma from your regular expression, and it matches.
preg_match_all('/\{ASK\((.*?)\)\}/', '{ASK(Value, Value, \'Sentence\', X)}', $matches);
print_r($matches);
//Explode the matched group
$exploded = explode(',',$matches[1]);
print_r($exploded);
/*
* Note that we used $matches[1] instead of $matches[0],
* since the first element contains the entire matched
* expression, and each subsequent element contains the matching groups.
*/
$s = "{ASK(Value, Value, 'Sentence', Some_Char)}";
$p = '#\{ASK\((.*?)\)\}#';
preg_match_all($p, $s, $matches);
print_r($matches);
Simply split & explode
$Myval = "{ASK(Value, Value, 'Sentence', Some_Char)}";
$splitedVal = split('[()]', $Myval);
$explodedVal = explode(",", $splitedVal[1]);
print_r($explodedVal);
// output
Array ( [0] => Value [1] => Value [2] => 'Sentence' [3] => Some_Char )
An easy way to do this (though not entirely contained within the regex) might be:
preg_match_all('/\{ASK\([^)]*\)\}/', '{ASK(Value, Value, \'Sentence\', X)}', $matches);
$values = explode($matches[1]);
So long as your Values, Sentences, and Chars do not contain , or ), then this single regex pattern will deliver without the extra explode() call.
Pattern: ~(?:\G, |ASK\()\K[^,)]+~ (Pattern Demo)
Code: (Demo)
$string="{ASK(Value, Value, 'Sentence', Some_Char)}";
print_r(preg_match_all('~(?:\G, |ASK\()\K[^,)]+~',$string,$out)?$out[0]:[]);
Output:
Array
(
[0] => Value
[1] => Value
[2] => 'Sentence'
[3] => Some_Char
)
The "magic" is in the \G. This tells regex to continue matching at the start of the string or just after the previous match. Here is a similar answer that I've posted: https://stackoverflow.com/a/48373347/2943403
Right now i'm trying to get this:
Array
(
[0] => hello
[1] =>
[2] => goodbye
)
Where index 1 is the empty string.
$toBeSplit= 'hello,,goodbye';
$textSplitted = preg_split('/[,]+/', $toBeSplit, -1);
$textSplitted looks like this:
Array
(
[0] => hello
[1] => goodbye
)
I'm using PHP 5.3.2
[,]+ means one or more comma characters while as much as possible is matched. Use just /,/ and it works:
$textSplitted = preg_split('/,/', $toBeSplit, -1);
But you don’t even need regular expression:
$textSplitted = explode(',', $toBeSplit);
How about this:
$textSplitted = preg_split('/,/', $toBeSplit, -1);
Your split regex was grabbing all the commas, not just one.
Your pattern splits the text using a sequence of commas as separator (its syntax also isn't perfect, as you're using a character class for no reason), so two (or two hundred) commas count just as one.
Anyway, since your just using a literal character as separator, use explode():
$str = 'hello,,goodbye';
print_r(explode(',', $str));
output:
Array
(
[0] => hello
[1] =>
[2] => goodbye
)