Preg_split and delimiter

[Mastodont]

Probably lamer question, but I really don't understand ... wanna break content of textarea into lines.

 

This works OK, each item of array contains one line:

 

$s = preg_split("\r?\n?", $_POST['...']);

 

Array ([0] => first [1] => second [2] => third )

 

With delimiters, array is composed from individual characters :-(((

 

$s = preg_split("/\r?\n?/", $_POST['...']);

 

Array ([0] => [1] => f [2] => i [3] => r [4] => s [5] => t [6] => [7] => s [8] => e [9] => c [10] => o [11] => n [12] => d [13] => [14] => t [15] => h [16] => i [17] => r [18] => d [19] => )

 

WTF? Thanks for explanation.

[dsaba]

~a?~

 

on:

hi
hi

 

yields:

Array
(
    [0] => Array
        (
            [0] => 
            [1] => 
            [2] => 
            [3] => 
            [4] => 
            [5] => 
        )

)

 

There are 6 characters including linebreaks in the haystack on an optional ? it will try to match it for each character in the haystack, and if not it will produce a null group/capture

This is what it looks like..

 

So \r? which is not found in your haystack (which you did not provide so i'm guessing based on my testing) It gives captures all null for each char it checks against

 

Also I noticed '\r?\n?' produces a parse php error that says it needs delimiters, while "\r?\n?" doesn't

 

 

Here are some interesting notes on the function:

http://us.php.net/manual/en/function.preg-split.php#59358

http://us.php.net/manual/en/function.preg-split.php#51209

[effigy]

Why would you use a pattern where everything is optional? Which type of line breaks do you need to look for?

[dsaba]

WTF? Thanks for explanation.

 

Do you have an explanation for this behavior, effigy?

[effigy]

WTF? Thanks for explanation.

 

Do you have an explanation for this behavior, effigy?

 

Sheer confusion mixed with mainstream lingo?

[dsaba]

Sheer confusion mixed with mainstream lingo?

 

so the reason why "\r\n" works as a pattern but this doesn't '\r\n'

and why \r?\n? yields so many subgroups

is because of sheer confusion & mainstream lingo?

 

[effigy]

I responded to what you quoted.

 

"\r\n" works as a pattern but this doesn't '\r\n'

 

'/\r\n/' works fine. You were missing delimiters.

 

why \r?\n? yields so many subgroups

 

Because everything is optional.

[dsaba]

this does not provide a parse error and there are no delimiters in the pattern:

preg_match("\r\n", 'hello
world');

[effigy]

Are your errors turned on? I get the following:

 

Warning:  preg_match() [function.preg-match]: Empty regular expression in ... on line ....