Can anybody help me for find next index of particular string ?

[Qt embedded developer]

i have one string like below:

QString str = Ddhh (copy)(1).txt;

i have to each time increase the 1 by 1. means if its 1 then i have to make it 2. if its 2 then i have tom make it 3.

can anybody suggest me way to achieve this with example ?

[J.Hilk]

@Qt-embedded-developer
because I'm feeling festive!
Here's a very crude and unoptimised way:

QString s{"Ddhh (copy)(1).txt"};

    for(int i {10}, j{50}; i < j; i++)
    {
        auto indexStart = s.lastIndexOf(QRegularExpression("\\(.+?\\)"));
        auto indexEnd = s.indexOf(QRegularExpression("\\)"), indexStart+1);

        QString left = s.left(indexStart +1);
        QString right = s.right(s.size() - indexEnd);

        int copyCount = s.midRef(indexStart +1, indexEnd - indexStart -1).toInt();

        s = left + QString::number(++copyCount) + right;
        qDebug() << s;
    }

[Qt embedded developer]

@J-Hilk Dear J-hilk. your code helped me but may i know the reason why you have taken for loop ?

[J.Hilk]

@Qt-embedded-developer as a, also very crude, Unit-Test. See if it works multiple times, and for multiple ranges of numbers