How to count a particular character in QString Qt

Question

Imagine I have a QString containing this:

"#### some random text ### other info
a line break ## something else"

How would I find out how many hashes are in my QString? In other words how can I get the number 9 out of this string?

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answer

Thanks to the answers, Solution was quite simple, overlooked that in the documentation using the count() method, you can pass as argument what you're counting.

Answer 1

You could use this method and pass the # character:

#include <QString>
#include <QDebug>

int main()
{
    // Replace the QStringLiteral macro with QLatin1String if you are using Qt 4.

    QString myString = QStringLiteral("#### some random text ### other info\n \
                                       a line break ## something else");
    qDebug() << myString.count(QLatin1Char('#'));
    return 0;
}

Then with gcc for instance, you can the following command or something similar to see the result.

g++ -I/usr/include/qt -I/usr/include/qt/QtCore -lQt5Core -fPIC main109.cpp && ./a.out

Output will be: 9

As you can see, there is no need for iterating through yourself as the Qt convenience method already does that for you using the internal qt_string_count.

Answer 2

Seems QString has useful counting methods.

http://qt-project.org/doc/qt-5.0/qtcore/qstring.html#count-3

Or you could just loop over every character in the string and increment a variable when you find #.

unsigned int hCount(0);
for(QString::const_iterator itr(str.begin()); itr != str.end(); ++itr)
    if(*itr == '#') ++hCount;

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C++11

unsigned int hCount{0}; for(const auto& c : str) if(c == '#') ++hCount;