Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
448 views
in Technique[技术] by (71.8m points)

java - Calling super() with no Superclass?

What happens (if anything) when a constructor calls 'super()' without having any superclass besides Object? Like so:

public class foo implements Serializable, Comparable {

  int[] startPoint;

  public foo() {

    super();

    startPoint = {5,9};
  }
}

Edit: So if this does nothing, why would anyone explicitly write that in code? Would it make any difference if I just delete that line?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

It is always OK to delete the line super(); from any constructor, and there is nothing particular about the constructors of classes that extend Object. The call of the nullary superclass constructor is always implied, so whether you write it down or not, you always get the exact same semantics.

Note that this means that if you omit a call to the superclass constructor that does something big, like start database connections or the whole GUI, all this will happen whether or not you actually write super();.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...