четверг, 5 июня 2014 г.

Java and frustration

Java is very complex language. At least for me. I often fall into frustration learning it, especially passing tests like SCJP.


Var args syntax:

1:    static void varArgs1(int... args){}  
2:    static void varArgs2(int[] args){}  

3:    public static void main(String[] args) {  
4:      varArgs1(10, 20, 30);  
5:      varArgs1(new int[]{10, 20, 30});   //oyw. ok  
6:      varArgs2(10, 20, 30); //compile error  
7:      varArgs2(new int[]{10, 20, 30});  
8:  }  


Also, in general, overloaded var-args methods are chosen last.

Strange array declaration

     int []myOddMassive[];    //correct!! wtf


Polymorphism is only for instance methods!!!:

class Parent {
    String name = "papa";
    void say(){
        System.out.println("where is my meat");}
}
class Child extends Parent{
    String name = "mimi";
    void say(){
        System.out.println("toy please");}
}

public class Main {

    public static void main(String[] args) {
        Parent p = new Child();
        p.say();
        System.out.println(p.name);
    }
}

output: 
toy please
papa

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