C++ syntax

[aamir121a]

In this line of C++ code ;

 int permissions = (mode == QSharedMemory::ReadOnly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS);

what does the question mark mean and the colon mean

[GNiewerth]

It´s the ternary operator, it´s syntax is "exp ? A : B". When the exp evaluates to true, its return value is A, else it´s B.

[GCDEF]

In this line of C++ code ;

 int permissions = (mode == QSharedMemory::ReadOnly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS);

what does the question mark mean and the colon mean

Think of it like

if(mode == QSharedMemory::ReadOnly)
    permissions = FILE_MAP_READ;
else
    permissions = FILE_MAP_ALL_ACCESS;

[aamir121a]

thank you all as always you have been most helpful