QByteArray ba = "The quick brown fox jumped over the lazy dog."; QByteArray oldText = "fox"; QByteArray newText = "cat"; ba.replace(oldText, newText);
QString str = "Hello, world!"; QByteArray ba = str.toUtf8(); QByteArray oldText = "world"; QByteArray newText = "Qt"; ba.replace(oldText, newText); str = QString::fromUtf8(ba);In this example, a QString is first converted to a QByteArray using the `toUtf8` function. The resulting QByteArray is then searched and replaced, and finally converted back to a QString using the `fromUtf8` function. In summary, the QCString replace function is a useful tool for searching and replacing substrings within a QByteArray. It is part of the Qt framework's QtCore package.