QString str = " 12 fff "；

QByteArray ba = str . tolatin 1()；

char * c = ba . data()；

Analysis:

To Latin 1QString to QByteArray method, Latin 1 stands for ASCII.

Const char*: a pointer to a character constant.

const？ Charles? *? ss=？ “XXXXXX”；

Indicates that what the pointer points to cannot be modified.

Charles? *? const？ ss？ =? “XXXXXX”； ?

Explain that this is a pointer constant and cannot point to other addresses, such as ss=? ... is not allowed.

const？ Charles? *? const？ ss？ =""? ; ?

The pointer cannot be modified, nor can the content it points to be modified.

Extended data:

Char array converted to QString:

char c[]= " 12ff "；

QString str = QString(qlatin 1 string(c))；

For strings:

/0 means terminator, for example, in an array added by C language, there is a default /0 at the end.

/0 is not a space,'' is a space.

Is an empty string.