how to convert QString into int in qt creator

Question

I have seen one answer regarding to this same question but when I tried it with my problem it get confused.

here is my string,

bit_rate = "bitrate: 2334 kb/s"

I need to get the 2334 from this string and assign it into a integer variable.. how is this possible in qt creator. I tried toInt(), but it always gives 0 as the answer.

possible duplicate of [How to convert QString to int?](http://stackoverflow.com/questions/16633555/how-to-convert-qstring-to-int) — Eitan T, Jul 08 '14 at 11:41
no thats the answer I mentioned above.but I couldn't use it as it is.due to suffix and prefix problem — Mlarnt90, Jul 08 '14 at 11:49

score 6 · Accepted Answer · answered Jul 08 '14 at 11:46

6

You need to get rid of the bitrate: prefix and kb/s suffix. The best way is to use QRegExp or QRegularExpression to extract the digit part of the string and then call toInt().

Here's example:

QString str = "bitrate: 3543 kb/s";
int value;

QRegExp re("bitrate:\\s*(\\d+)\\s*.*");
if (re.indexIn(str) != -1) {
    value = re.cap(1).toInt();
} else {
    qDebug() << "String not matched.";
    return;
}
qDebug() << value;

answered Jul 08 '14 at 11:46

Googie

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thanx that exactly gave me the answer I wanted. – Mlarnt90 Jul 08 '14 at 11:54
thanx @Googie for your answer. Because of it, I tend to use regular expressions for other parts in my code. – Mlarnt90 Jul 09 '14 at 03:53

score 2 · Answer 2 · answered Jul 08 '14 at 11:59

2

The reference page has a ton of material on this. The easiest way to implement this is to split the string based on spaces, then convert the one you want to an Int.

Example:

QString str = "bitrate: 3543 kb/s";
QStringList lst = str.split(" ");
Int value = lst[1].toInt();

answered Jul 08 '14 at 11:59

kwierman

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oops I was being silly. thanx ur answer gave me the result very easily..thank you very much. – Mlarnt90 Jul 08 '14 at 12:10
@Mlarnt90 so the answer to duplicate question didn't help you? It's basically the same as this one. – Eitan T Jul 08 '14 at 14:16

score 1 · Answer 3 · answered Jul 08 '14 at 12:19

1

QTextIStream stream("bitrate: 3543 kb/s");
QString prefix, sufix;
int result;
stream >> prefix >> result >> sufix;

answered Jul 08 '14 at 12:19

Marek R

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how to convert QString into int in qt creator

3 Answers3