QRegExp: Last sign has to be a number

[forenued]

Hello,

i need a regular expression that ensures that the last sign in a QString is a digit and i tried the following code:





QRegExp rx ("[0-9]$");

cout << rx.exactMatch("123") << endl;



i always get false as result, but i don't understand why?

Can anybody tell me what i'm doing wrong?

Thank you very much!

[Moppel]

Can't test but I think this should work:



QRegExp rx (".*[0-9]$");



Your regexp should match this:


cout << rx.exactMatch("3") << endl;

Does this match?
If so, [0-9]$ machtes one and only one digit (exactMatch)
[0-9] can be written as \d as well, just follow the link to QRegExp

[forenued]

Thank you for your answer! But with this i get an invalid expression. The error string is:



not valid!: bad repetition syntax


Added after 47 minutes:

Ah, it works with



QRegExp rx (".*[0-9]$");


Thank you very much, Moppel and have a nice day!!

[anda_skoa]

Alternatively you could check if the last character is a digit.

Cheers,
_

[jefftee]

With any new code you should look at and use (IMHO) QRegularExpression over QRegExp.

[anda_skoa]

I agree but using any kind of regular expression looks wasteful if the requirement is to just check the last character, which is basically just an "isDigit" check on the last QChar in the string.

Cheers,
_

[jefftee]

I agree but using any kind of regular expression looks wasteful if the requirement is to just check the last character, which is basically just an "isDigit" check on the last QChar in the string.
I agree, just couldn't tell if it was a homework assignment for regular expressions, etc!