CODEWITHSUNDEEP
javaregex
La bla bla
La bla bla

Reputation: 8708

regex restrict to one semicolon

I'm making a code which takes a file and checks if it's a valid Java code, must be done using regexes.

I run over every line and checks if it end with ; or { or }. however, I can't seem to manage to limit it to only 1 occurence of it. i.e both

int i=0;

and

int i=0 ;;;;;;;

would pass.. The regex I'm using right now is

.+;{1}\\s*$

tried many other options, non seems to work. any help would be great! Thanks

Upvotes: 1

Views: 1874

Answers (3)

Matzi
Matzi

Reputation: 13925

If you want to make sure, that there is only one semicolon in the whole row, then use:

^[^;]+;{1}\\s*$

This is not a proper check for a valid java source however.

Upvotes: 0

GenericJon
GenericJon

Reputation: 8986

Your problem is that the . will also match a semicolon, so your expression will match all but the last semicolon as part of the .+.

To avoid this, you could match any character except a semicolon by using [^;]. i.e.

[^;]+;\\s*$

However, you should be aware that int i=0 ;;;;;;;;; is perfectly valid Java code.

Upvotes: 2

Bruno
Bruno

Reputation: 94

This part of the regexp: .+ will match any character, including all but the last of your ;'s.

You need to exclude ; from the first part of your regexp so that you can match "Anything but a ; followed by exactly one ;" (and once you get that working, you can expand your character class to capture also { and } if you wish)

HTH

Upvotes: 0

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