1.4 certification objectives

[Matthias Wendel]

In a 1.4 mock exam I found:

What will the output of the following program:

    
public class Test1 {
      static{
           System.out.println("Static");
      }
      {
           System.out.println("Instance");
       }
       public void Test1(){
           System.out.println("Constructor");
       }
       public static void main(String[] args) {
          Test1 t = null;
       }
}
 

Can anyone tell me to wich (1.4)Certification objective this question refers?
Regards,
Matthias

[marc weber]

These unnamed blocks are initializer blocks, which I think fall under "Language Fundamentals."

If the block has a "static" modifier, it will execute when the class is loaded. Otherwise, without a "static" modifier, the block will execute when an instance is initialized (before the body of the constructor).

I've modified the code to demonstrate this. Note that when an instance is created, the non-static initializer block executes before the constructor body. Also note that the static block only executes once, when the class is loaded (which happens when the static main method is invoked). So creating a second instance does not cause the static block to execute again.

public class Test1 {
  //static initializer block...
  static {
    System.out.println("static block");
  }
 
  //non-static initializer block...
  {
    System.out.println("instance block");
  }
 
  //constructor (no return type)...
  Test1() {
    System.out.println("Constructor");
  }
 
  public static void main(String[] args) {
    //calling constructor...
    Test1 t1 = new Test1();
    Test1 t2 = new Test1();
  }
}

[Bert Bates]

What's interesting is that init blocks are on the 5.0 exam but they're NOT on the 1.4 exam!

Anyway, I would strongly recommend that you study for the 5.0 exam, not the 1.4.

[Matthias Wendel]

It's because I'm under pressure what concerns my resources of preparation time. And everybody is saying the 5.0 exam is more difficult. What are the main arguments to do the 5.0 exam?
Regards,
Matthias

[Jesper de Jong]

The current version of Java is version 6, and it has been out for almost a year already. So with Java 1.4 you are two releases behind the current version.

In Java 5, a whole list of new language features have been added. More and more Java projects are being done with Java 5 or Java 6, and if you're going to work on such a project you'll be expected to know those new features.

So an SCJP 5 certificate is worth more and will last longer because it's more current.

Suppose you're on a job interview and you're asked "Why did you do SCJP 1.4 instead of SCJP 5?". Are you then going to answer "Because it is easier"? That wouldn't leave a good impression...
[ November 08, 2007: Message edited by: Jesper Young ]

[Matthias Wendel]

Thank you - I'll think it over.
Regards,
Matthias