Is there any difference between QRegularExpression and QRegExp?

c++ qt qt5 qregexp
sashoalm picture sashoalm · Apr 9, 2015 · Viewed 10.8k times · Source

I see there is a new class for regular expressions - QRegularExpression. Is it just a typedef for QRegExp, or a new class, or what? And why do we need it, we already have QRegExp?

Answer

sashoalm picture sashoalm · Apr 9, 2015

Ok, after some more digging into the docs, I found it really is a new class, it has improvements, but it is only available in Qt5, so you can't use it if you want to compile on both Qt4 and Qt5:

Notes for QRegExp Users

The QRegularExpression class introduced in Qt 5 is a big improvement upon QRegExp, in terms of APIs offered, supported pattern syntax and speed of execution. The biggest difference is that QRegularExpression simply holds a regular expression, and it's not modified when a match is requested. Instead, a QRegularExpressionMatch object is returned, in order to check the result of a match and extract the captured substring. The same applies with global matching and QRegularExpressionMatchIterator.

Related questions

How to create/read/write JSON files in Qt5

Qt5 has a new JSON parser and I want to use it. The problem is that it isn't too clear about what the functions do in layman's terms and how to write code with it. That or I could be …

Read More
Qt5 Static Build yields Failed to load platform plugin "windows"

I am writing a Qt application on Windows using Visual Studio 2012. Using the Qt Add-in and a custom built static distribution of Qt 5.0.2. I am running into the dreaded "Failed to load platform plugin windows" error whenever I run the …

Read More
cmake does not find qt 5.1.1

I just installed the Qt 5.1.1 for Windows 32-bit (MinGW 4.8, OpenGL) and tried to add it to my cmake. But CMake just does not want to find it and i dont know why. What am i missing? Do i need to …

Read More