I want to get QString from another QString, when I know necessary indexes.
For example:
Main string: "This is a string".
I want to create new QString from first 5 symbols and get "This ".
input : first and last char number.
output : new QString.
How to create it ?
P.S. Not only first several letters, also from the middle of the line, for example from 5 till 8.
Answer
If you do not need to modify the substring, then you can use QStringRef. The QStringRef class is a read only wrapper around an existing QString that references a substring within the existing string. This gives much better performance than creating a new QString object to contain the sub-string. E.g.
QString myString("This is a string");
QStringRef subString(&myString, 5, 2); // subString contains "is"
If you do need to modify the substring, then left(), mid() and right() will do what you need...
QString myString("This is a string");
QString subString = myString.mid(5,2); // subString contains "is"
subString.append("n't"); // subString contains "isn't"