a slightly better PCRE question

[Twey]

1. How is it that '/[^\d-]*(-)[^\d-]*/' is not greedy?

It is greedy, but it can't match hyphens because they're included in the negative character class.

2. In the following 3-,-,,-,,,-,,,,-,,,,,-4,5 what is the last match? I guess I am still trying to wrap my mind around the 0 or more quantifier.

For which pattern?

[james438]

'/[^\d-]*(-)[^\d-]*/'

for this one as applied to 3-,-,,-,,,-,,,,-,,,,,-4,5.

It is greedy, but it can't match hyphens because they're included in the negative character class.

Sorry, dumb question, but if it is ungreedy, wouldn't it replace the 4 as well? The way I understand the above expression it will match everything between the first [^\d-]* and the last [^\d-]*.

[Twey]

The last match will be ",,,,,-".

Sorry, dumb question, but if it is ungreedy, wouldn't it replace the 4 as well?

If it were ungreedy it definitely wouldn't. As it stands, it can't -- 4 matches one of the characters in the negative character class.

[james438]

I misspoke (sp?) I meant greedy. Getting sleepy I am afraid. If it is greedy wouldn't it match 3-,-,,-,,,-,,,,-,,,,,-4,-5 and everything in between? or does the negative class automatically apply to that which is between the two matches.

I changed the example slightly.

EDIT: wait. Let me try something. I don't think I thought it through before speaking.
I am currently studying the difference between [].*[] and [].*?[] and [].*?[]? and [].*[]? Once I understand that I will know the answer to my own question.

[Twey]

does the negative class automatically apply to that which is between the two matches.

You're looking at it the wrong way. * means repeat: everything contained therein is part of the match, and has to match the repeated expression. If you have /ba*b/ it's not the same as /ba.*ab/. It can't match ",-,,-,,,-,,,,-,,,,,-4,-" because that contains more than one hyphen (the hyphen isn't repeated in the expression; the hyphen in the negative character class exists for this purpose) and a digit, which it cannot match under any circumstances.

[james438]

yeah... I know. I am kinda embarrassed at my questions really. I am going back to some of the basics of regexp again and practicing some basic examples for a bit till I can do this a little faster in my head.

I really just need to work on this on my own for a bit.