A.The equals method does NOT properly override the Object.equals method.
B.Compilation fails because the private attribute p.name cannot be accessed in line 5.
C.To work correctly with hash-based data structures,this class must also implement the hashCode method.
D.When adding Person objects to a java.util.Set collection,the equals method in line 4 will prevent duplicates.

A.The value "4" is printed at the command line.
B.Compilation fails because of an error in line 5.
C.Compilation fails because of an error in line 9.
D.A NullPointerException occurs at runtime.
E.A NumberFormatException occurs at runtime.
F.An IllegalStateException occurs at runtime.

A.Compilation fails.
B.pi is bigger than 3.
C.An exception occurs at runtime.
D.pi is bigger than 3. Have a nice day.
E.pi is not bigger than 3. Have a nice day.

A.Line 33 must be called within a try block.
B.The exception thrown by method 1 in class A is not required to be caught.
C.The method declared on line 31 must be declared to throw a runtime exception.
D.On line 5 of class A,the call to method 2 of class B does not need to be placed in a try catch block.

A.no output
B.no outputassert is on
C.assert is on
D.no outputAn AssertionError is thrown.
E.assert is onAn AssertionError is thrown.

A.5，6
B.5，5
C.6，5
D.6，6

A.The instance gets garbage collected.
B.The code on line 33 throws an exception.
C.The code on line 35 throws an exception.
D.The code on line 31 throws an exception.
E.The code on line 33 executes successfully.

A.a
B.b
C.c
D.ac
E.abc

A.test end
B.Compilation fails.
C.test runtime end
D.test exception end
E.A Throwable is thrown by main at runtime.

A.00
B.0001
C.000120
D.00012021
E.Compilation fails
F.An exception is thrown at runtime

A.Alpha a = x；
B.Foo f = （Delta）x；
C.Foo f = （Alpha）x；
D.Beta b = （Beta）（Alpha）x；