JAVA題庫:格林模擬試題三（上）(5)

question 15)which of the following statements are true?

1) constructors cannot have a visibility modifier
2) constructors can be marked public and protected, but not private
3) constructors can only have a primitive return type
4) constructors are not inherited
 

question 16)what will happen when you attempt to compile and run the following class?

class base{base(int i){ system.out.println("base"); }}class severn extends base{public static void main(string argv[]){ severn s = new severn(); }void severn(){ system.out.println("severn"); }}

1) compilation and output of the string "severn" at runtime
2) compile time error
3) compilation and no output at runtime
4) compilation and output of the string "base"

question 17)which of the following statements are true?
 

1) static methods do not have access to the implicit variable called this
2) a static method may be called without creating an instance of its class
3) a static method may not be overriden to be non-static
4) a static method may not be overloaded