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I have made class that convert QList<qreal> (very big list) to JSON string, but it generates a extra large text.

Here is code:

QJsonObject rootObject;
rootObject.insert("Test",0.05);
qDebug()<<QJsonDocument(rootObject).toJson(QJsonDocument::Compact);
And I have tried equal code:
QJsonObject rootObject;
rootObject.insert("Test",QString("0.05").toDouble());
qDebug()<<QJsonDocument(rootObject).toJson(QJsonDocument::Compact);
And debug ouptut is always:
{"Test":0.050000000000000003}
I want to get short output like this:
{"Test":0.05}
Is there way to fix QJsonDocument? Or make some decimals count rounding/limit?
                @Merlin069 because all my input data has come from double value that converted from QString. And it is a proof that bug is not in that toDouble conversion.
– IGHOR
                Nov 5, 2014 at 17:11
                I see, since you missed the quotes around 0.05 passed into QString, I didn't realise that the input was originally a string. I've tested QVariant and that works, so you're right that the json conversion is the problem. It's not ideal, but you could write a string, instead of the double.
– TheDarkKnight
                Nov 5, 2014 at 17:30
This prints out 0.5, as expected.
However, I think the problem is due to floating point precision. QJSonDocument is representing the number as accurately as possible, but does not have a function to limit the number of decimal places represented, as is present in QString.
Though not ideal, if your really want 0.5 represented this way, you can write a string value instead of the double.
                Single value looks ok, but I need to get valid json string with names and values. So I used QJsonArray and QJsonDocument to convert all to string. Looks like it QJsonDocument problem only.
– IGHOR
                Nov 5, 2014 at 17:55
                I just need to convert QJsonObject to valid JSON string. QJsonObject contains this doubles and output is to large. Some doubles converted correcty, but I have tested 0.5 and it always huge.
– IGHOR
                Nov 5, 2014 at 18:02
        
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