[c++] Read a text file line by line in Qt

How can I read a text file line by line in Qt?

I'm looking for the Qt equivalent to:

std::ifstream infile;
std::string line;
while (std::getline(infile, line))
{
   ...
}

Since Qt 5.5 you can use QTextStream::readLineInto. It behaves similar to std::getline and is maybe faster as QTextStream::readLine, because it reuses the string:

QIODevice* device;
QTextStream in(&device);

QString line;
while (in.readLineInto(&line)) {
  // ...
}

Here's the example from my code. So I will read a text from 1st line to 3rd line using readLine() and then store to array variable and print into textfield using for-loop :

QFile file("file.txt");

    if(!file.open(QIODevice::ReadOnly | QIODevice::Text))
        return;

    QTextStream in(&file);
    QString line[3] = in.readLine();
    for(int i=0; i<3; i++)
    {
        ui->textEdit->append(line[i]);
    }

QFile inputFile(QString("/path/to/file"));
inputFile.open(QIODevice::ReadOnly);
if (!inputFile.isOpen())
    return;

QTextStream stream(&inputFile);
QString line = stream.readLine();
while (!line.isNull()) {
    /* process information */

    line = stream.readLine();
};