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Does run() method is declard i Thread?
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Maciej Zpolski
Greenhorn
Joined: Nov 02, 2006
Posts: 10
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Hi, There is a question in MasterExam: Which of the fallowing methods are defined in the Thread class? Answer is: run() and start() But Thread implements Runnable, which declares method run(). Does it mean, that when a class implements an interface, it defined method from that interface, but when it extends other class and overrides or not method from that class it don't defined that methods?
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Sorry for my english..
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Sanjeev Singh
Ranch Hand
Joined: Nov 01, 2006
Posts: 381
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Maciej, In my opinion start() is only defined in Thread class.run() is a part of Runnable interface.
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~Sanjeev Singh<br />SCJP 1.5
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Henry Wong
author
Sheriff
Joined: Sep 28, 2004
Posts: 16681
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Originally posted by Maciej Zpolski: But Thread implements Runnable, which declares method run(). Does it mean, that when a class implements an interface, it defined method from that interface, but when it extends other class and overrides or not method from that class it don't defined that methods?
I am not completely sure what you are asking... but if I assume correctly... No. If a class implements an interface, it doesn't have to provide the implementations for the interface. The implementation may be from a class that it inherits from, or the class may be abstract. Henry
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Books: Java Threads, 3rd Edition, Jini in a Nutshell, and Java Gems (contributor)
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Maciej Zpolski
Greenhorn
Joined: Nov 02, 2006
Posts: 10
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I try in different way interface A{ void method1(); } class B{ void method2(){} void method3(){} } class C extends B implements A{ public void method1(){} void method2(){} } Which of fallowing methods are defined in class C? 1) method1() 2) method2() 3) method3() I think that 1) and 2), because they are given explicity in C. Am I right?
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Sanjeev Singh
Ranch Hand
Joined: Nov 01, 2006
Posts: 381
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No,I disagree It is the interface A and class B which gave birth to these methods.Class C is only taking the legacy from their parents.
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Maciej Zpolski
Greenhorn
Joined: Nov 02, 2006
Posts: 10
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Comparing to MasterExam answer for question about Thread: 1) is correst (run() is defined in Thread) 3) is incorrect (wait() isn't defined in Thread) But what about 2)?
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subject: Does run() method is declard i Thread?
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