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Write data from csv to float array

  • I have CSV file with 2 columns and 20 rows, how to write each column in to two float arrays. For example i could do it with QVector, but how to do it with arrays, there is array Fi and Lyamda.And how to convert QStringlist to Float?

    float Fi[20];
    float Lyamda[20];
    int rowCount=0;
    QString line;
    QStringList qList;
    QFile File("F:\\data.csv");
    QVector<float> z;
        QTextStream out(&File);


  • Lifetime Qt Champion

    Why do you want c type array?
    Its rarely it would offer any benefits over std::vector or Qt versions.

    Anyway, you need to keep track free index to insert in.

    // rest
    int FiFree=0;

    while(!out.atEnd()) {
    Fi[FiFree++] = qList[1].toFloat();

    • .And how to convert QStringlist to Float?
      You mean each string in the list to a float value?
      Just loop it over and use toFloat().

  • Qt Champions 2017

    int i=0;
    while(!file.atEnd()) {
    QString line = file.readline();
    QStringList cols = line.split(",");
    fi[i] =;
    lamada[i++] =;

  • @mrjj i tried this doesn't work Fi[FiFree++] = qList[1].toFloat();

  • Lifetime Qt Champion

    In what didnt work ?

  • @mrjj after qList[1] i can't put dot, there is no functions for qList[1].
    P.S sorry for my english if i can't explain

  • Lifetime Qt Champion

    but it does know qList ?
    Just type toFloat() then.

    it does work.
    This compiles and write expected output.

    #include <QStringlist>
    #include <qDebug>

    float list[10];
    QStringList strlist;
    strlist << "1.122";
    qDebug() << list[0];

    Ahh i see what you mean.
    in my sample, it wont auto complete anything on
    At all. Must be a bug.

  • @mrjj yes there is no auto complete afer qList[0], oh sorry i forget to tell you, that mr.Dhreerendas code work, this is what i wanted. Thank you

  • Great thanks to you both.

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