CODEWITHSUNDEEP
qt
cihad
cihad

Reputation: 84

my qvector size is 5 but I get 10 output

in first for loop when I wrote z.size() I get

Qt has caught an exception thrown from an event handler. Throwing exceptions from an event handler is not supported in Qt. You must reimplement QApplication::notify() and catch all exceptions there.

and also in second for when I wrote z.size I get 10 output but size of z is 5 as you can see. What is wrong .First 5 output is 0 and then rest is normal like 0 1 2 3 4 but I should have 5 output am I wrong

QVector<int> z(5);
for(int i=0;i<5;i++)
    z.push_back(i);
QString str;
for (int i = 0; i < z.size(); ++i)
{
    if (i > 0)
        str += " ";
    str += QString::number(z[i]);
}
ui->mbox->setText(str);

}

Upvotes: 0

Views: 492

Answers (2)

user362638
user362638

Reputation:

When you create the QVector z, you give the initial size of 5. That means that the vector contains 5 zeroes. Then you add five more ints, from 0 to 4. The fix is to change

QVector<int> z(5);

to

QVector<int> z;

Most often, QVector is not the best container to use, usually QList is much better. From Qt's documentation:

For most purposes, QList is the right class to use. Its index-based API is more convenient than QLinkedList's iterator-based API, and it is usually faster than QVector because of the way it stores its items in memory. It also expands to less code in your executable.

Upvotes: 1

Neoh
Neoh

Reputation: 16164

for(int i=0;i<5;i++)
z.push_back(i);

You just added 5 elements into the array.

Upvotes: 0

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