Regular expression: Match lonely double quotes

Asperamanca

I am looking for a regular expression that matches lonely double quotes, i.e.
abc" // <-- match
abc"" // <-- no match

Based on an example replacing & with & from QRexExp, I tried:
QRegExp exp(QString("\"(?!\")"));

But that does not even match a lonely double quote.

Where have I gone wrong?

SGaist

Hi,

To ensure your double quote is single you need a lookahead and a lookbehind condition. In this case QRegExp is not the right tool. You need to switch to QRegularExpression and use "(?<!\")\"(?!\")"

Asperamanca

@SGaist
Thank you for the hint. Strangely, I had looked through the QRegularExpression help file for lookahead, but could not find anything. Given the complexity of the class, I probably gave up too early :-)

SGaist

QRegularExpression's regexp engine is PCRE so you should be able to use features from it.

There's also the regular expression tool that you can build and use to test your regular expressions.