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Interface Ques

Ishaan Mohan
Ranch Hand

Joined: Jan 20, 2001
Posts: 115
Which of these statements about Interfaces are true ?
a) Interfaces are abstract by default.
b) An Interfaces can have static members.
c) All methods in an interfaces are abstract although you need
not declare them to be so.
d) Fields of an Interface may be declared as transient or
volatile but not Synchronized.
e) Interfaces cannot be final.
Answer given are a and c.
My question is why not e ?
Interfaces are abstract so they cannot be final.
Pls. clarify this.
huiying li
Ranch Hand

Joined: Feb 12, 2001
Posts: 68

b) An Interfaces can have static members.
e) Interfaces cannot be final.
I think the answer should be a, b, c, e.
b) is right because interfaces can define constance and they are public static and final
e) is correct because interfaces are abstract and therefore can not be final Mugal's book page 111, states this explicitly.

Hima Mangal
Ranch Hand

Joined: Feb 25, 2001
Posts: 82
i think a,b,c are right..
interfaces cannot be final becasue that will mean that one can't extend an interface under any circumstances , which is not possible.. and not mentioned anywhere in JLS.. i guess..

Hima<BR>Sun Certified Java Programmer
Rana Thakur

Joined: Feb 26, 2001
Posts: 26
For the choice b, if it is member variables in an interface then they are public, static and final, even if not stated. However, interface cannot have static member functions.
Ishaan Mohan
Ranch Hand

Joined: Jan 20, 2001
Posts: 115
Thanks everyone.
I agree. Here's the link:
subject: Interface Ques
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