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330 Java Tips.pdf - FTP Server

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General <strong>Java</strong> Questions II<br />

public class Test {<br />

public static void main(String[] args) {<br />

Start s = new Start();<br />

}<br />

}<br />

Answer: Because you have included the return-type 'void' in the method declaration,<br />

it becomes a normal method, that just happens to have the same name as the class -<br />

so it won't get used as a constructor. Remove the 'void' and it should work.<br />

--<br />

Vince Bowdren<br />

P.S. by John: If you do not specifically define any constructors, the compiler inserts<br />

an invisible zero parameter constructor "behind the scenes". Often this is of only<br />

theoretical importance, but the important qualification is that you only get a default<br />

zero parameter constructor if you do not create any of your own.<br />

Your program used this zero parameter constructor and you saw nothing...<br />

Q: Why we can not declare constructor as final ?<br />

Answer: The keyword final when dealing with methods means the method cannot be<br />

overridden.<br />

Because constructors are never inherited and so will never have the oportunity to be<br />

overridden, final would have no meaning to a constructor.<br />

Q: In <strong>Java</strong>, does exist a function like sprintf in C ?<br />

Answer: http://www.efd.lth.se/~d93hb/java/printf/index.html a free <strong>Java</strong> version of<br />

fprintf(), printf() and sprintf() - hb.format package<br />

Q: If I declare an array of an objects, say Dogs, is that memory taken when I<br />

create the array or when I create the objects in the aray when I declare this array:<br />

Dog[] dog = new Dog[100];<br />

or does it take the memory when I actually create the Dogs in the array eg:<br />

for(int i = 0;i

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