"C + + Primer (fifth edition)"

# commonly used in ACM: To determine whether the entire read process is over. (p280)

 while (CIN >> word)     // read operation succeeded ...

This method is inefficient and is more efficient in this way: "ACM Notes" No.4 http://www.cnblogs.com/fengyubo/p/4769254.html

# <fstream> defines three types to support file IO (p283)

Ifstream Read

Ofstream Write

FStream Reading and writing

Fstream::open (s)    //  Open File Sfstream::close ()    // close File

# Q: Why does C + + not put the file type into a built-in initialization of an object-like Cin, cout, Cerr? Inspiration

A: Because there are only three standard IO streams--each corresponding to the file descriptor 0, 1, 2--, but the user may read and write at the same time the file is not necessarily only one copy.

# You can use a derived class object as its base class object. (p279)

# You can bind a pointer or reference to a base class on a derived class object. (p534)

"C + + Primer (fifth edition)"