Quote

ap2000ap

Some functions are written like this
istream&operator >> ();
What does&mean? Why is the return value a reference?

chengwei2537

So that you can write
cout << "DDD" << "ddd" << endl;
Similar code

greenyard

Efficient and save memory

zfy010317

Handsome is one of the reasons.
The second is to refer to non-copying objects (that is, not copying functions), not all objects support copying.

番薯干

The use of reference return values ​​can avoid generating a temporary object to receive the return value, which means that it avoids calling the copy constructor, reducing memory consumption, and it is very efficient, while achieving stream operations

taindi11

The return value of the function is a reference to the stream object
This can be used multiple times
I just want cout<<" "<<"a"<<endl;

ymls888

Streams cannot be copied, so a reference must be returned.