In Java:

Override toString$()$ for both implementations of QueueADT, where the front value will be printed on the left. $($Notice that AQueue uses a circular array$)$

toString$()$ do not change the internal state of the queue.

Example:

QueueADT listQ $=$ new LQueue$(4)$;

listQ.enqueue$(1)$;

listQ.enqueue$(2)$;

listQ.enqueue$(3)$;

listQ.enqueue$(4)$;

listQ.dequeue$()$;

listQ.dequeue$()$;

listQ.enqueue$(5)$;

System.out.println$($listQ$)$;

$//$ Should print: $345$

QueueADT arrQ $=$ new AQueue$(4)$;

arrQ.enqueue$(10)$;

arrQ.enqueue$(20)$;

arrQ.enqueue$(30)$;

arrQ.enqueue$(40)$;

arrQ.dequeue$()$;

arrQ.dequeue$()$;

arrQ.enqueue$(50)$;

arrQ.enqueue$(60)$;

System.out.println$($arrQ$)$;

$//$ Should print: $30405060$