Core Java perguntas e respostas de entrevista
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Pergunta 131. Why isn't there operator overloading?
Because C++ has proven by example that operator overloading makes code almost impossible to maintain. In fact there very nearly wasn't even method overloading in Java, but it was thought that this was too useful for some very basic methods like print(). Note that some of the classes like DataOutputStream have unoverloaded methods like writeInt() and writeByte().
Pergunta 132. Can a method be overloaded based on different return type but same argument type ?
No, because the methods can be called without using their return type in which case there is ambiquity for the compiler
Pergunta 133. What restrictions are placed on method overloading?
Two methods may not have the same name and argument list but different return types.
Pergunta 134. How could Java classes direct program messages to the system console, but error messages, say to a file?
By default, both System console and err point at the system console.Stream st = new Stream (new FileOutputStream ("withoutbook_com.txt"));
System.setErr(st);
System.setOut(st);
Pergunta 135. What does the keyword "synchronize" mean in java. When do you use it? What are the disadvantages of synchronization?
Synchronize is used when you want to make your methods thread safe. The disadvantage of synchronize is it will end up in slowing down the program. Also if not handled properly it will end up in dead lock.
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Mais uteis segundo os usuarios:
- How could Java classes direct program messages to the system console, but error messages, say to a file?
- What are the differences between an interface and an abstract class?
- Why would you use a synchronized block vs. synchronized method?
- How can you force garbage collection?
- What are the differences between the methods sleep() and wait()?