Queue empty or not

[lost110]

So my friend is saying to write :

   if (front == - 1 || front > rear)
 {
      cout<<"Queue Underflow "
 }

to check the queue is empty or not! But don't you think that

if (rear == -1)
 {
      cout<<"Queue Underflow "
 }

is enough?. Because rear is gonna increment only after each push!

[deleted account xyzzy]

Your question is very light on details. Details you need to tell us so we can help you.

If you are using a std::queue, use the container's empty() member function to find out if it is empty.

http://www.cplusplus.com/reference/queue/queue/empty/

If you are using some other type of container, one that isn't part of the C++ standard library, ask your friend.