pattern matching

rebecca

what does (.+?)
mean?

how about (.+?@.+?)
?

thank-you,
rebecca

Anon

These are called Regular Expressions (regex). They should really be called H-uh?! =)

It is used to match patterns. I'm no expert, so i could be misreading the pattern, but...

(.+?) means the pattern may have one or more dots

(.+?@.+?) means the pattern may have one or more dots followed by @ followed by the same " may have one or more dots"

dannys

Slight misreading there - it's actually:

. : matches any charactor except newline
+ : match the preceding charactor 1 or more times
? : match the preceding charactor zero or one times

Basically all that pattern does is check that there is a @ sign somewhere in the string!

If it's supposed to check email addresses (which I'm assuming it is) a better regexp would be:

^{[a-zA-Z0-9_-.]+@[a-zA-Z0-9-]+.[a-zA-Z]+.?[a-zA-Z]+$}

This pattern requires the email address to have a combination of letters, numbers, fullstops, hyphens or underscores (username part) followed by an @ sign followed by more letters, numbers or hyphens (hostname part) followed by a fullstop then the domain (letters only) with an optional fullstop and more letters (to handle domains such as .co.uk)

Hope this helps

dannys

Ok, that should actually be :

^{[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z]+.?[a-zA-Z]+$}

rebecca

thanks to you both. I'm trying to decipher some sample code. I usually try to search for the meaning of each pattern symbol in my perl reference but you've saved me hours of squinting and shaking my head - much appreciated :-)

rebecca

Anon

Danny's right, I goofed ... like I said I probably did. =)

In order for the . to be a literal 'dot', it would have to be escaped with a slash. Otherwise . is a wildcard.