Code of Regular expression

emmi12345

hi ,

could any one explain wat this pattern will do

/([\w\W].*)/i

i did my work but cant understand logic

bubblenut

match any word character or non-word character (equates to any character) followed by any number of any characters. Also the i modifier at the end says "case insensitive" which makes no difference as you've specified no cased caracters (letters).
It matches everything, if that is what you wish (seems a little pointless to me) then this would be easier '/(.*)/'

What is the regex supposed to be doing?

Bubble

laserlight

hmm... where did you get this from?
\w should match a "word" character, and "\W" a "non-word" character.
So using both in a character class should be equivalent to matching any character.
(exclude newlines though, I'm not too sure about them)

So the pattern could be simplified to:
/../i
Now is the 0 or more quantifier, meaning that the preceding character is matched [0, infinity} number of times.
The ending i is to make the pattern case insensitive, but is sort of redundant here since we're matching anything.
Effectively, it looks like the pattern could be further simplified to:
/.+/
as + is the 1 or more quantifier.
This would then match a string that contains at least 1 character.
Using regular expressions for this is probably superfluous, since [man]strlen/man would do just as well.
Or even testing for !empty($str{0}), where $str is the string in question.

Disclaimer: I'm not an expert on regex....

EDIT:
oh yes, there's also a subpattern to it, but the subpattern is the whole pattern anyway.
So instead of having to use a back-reference, you can simply use the original string, excluding the regex delimiters (i.e. the starting and ending '/')

emmi12345

hi bubblenut ,

thx for ur reply, u suggest me to write /(.*)/ rather than i wrote but problem is that i want to read this string

"h r u 1 (body) abc"

if i exclude () it works gr8 with .* but with () it didnt give result thats y by hit and try i got the solution, do u have better solution to read () in string.

bubblenut

What are the restrictions you want to place on the match, are there any patterns which must be present in the string for it to match. For example; must the string have a matched pair of parentheses ( ) with at least one alphanumeric character inside? Must the first character be alphanumeric? Must the last character be alphanumeric? What is the pattern you are trying to match?

emmi12345

hi bubblenut,

i am matching this patterns

"you r unsubscribe from (body) and (spam)"

i want to pick this whole line including parenthesis.

bubblenut

No, you're missing my point. What is it about this line which tells you "this is the line that I want" as aposed to any other line?

emmi12345

ok sorry

the whole line is like that

"[0.4 spam policy] you r unsubscribe from (body) and (spam)"

and i want that after [0.4 spam policy] i pick whole line which consist parenthesis also

thx

bubblenut

right so if the line begins with the string "[0.4 spam policy]" we grab the rest of the line?

$string;//this variable is holding the string we want to search

if(preg_match('/^\[0\.4\sspam\spolicy\](.*)$/im',$string,$matches)) {
  echo('The regex matched "'.$matches[1].'"');
} else {
  echo('There was no match');
}

Right let's explain what's going on starting with the two modifiers the m means that ^ and $ match at the begining and ends of lines as well as the string as a whole and i means that the regex is case insensitive.
Right so onto the regex the ^ at the begining says "match if we're at the begining of the string or a new line" then we match the exact string "[0.4 spam policy]" and then parentheses which allow us to grab the next piece of the regex in the $matches array. the .* in the parentheses will match all characters appart from the new line character. The $ at the end is superfluos really but I like to keep it in just so when reading the meaning is clear (Q: Why is the ending $ superfluous?)

HTH
Bubble