Question

E.g. :

public class ClassA extends ClassB { 


public void run() {
  super.execute();
 ...................

Method execute exists only in ClassB.
Does it make sense to use:

super.execute();

may be enough:

execute();

?
Thanks.

Answer 1

Reasons:

1. Predictability (safety?) – if one day somebody implements ClassA.execute(), the code will work differently. This is also the case even is somebody subclasses ClassA and overrides execute(), leaving ClassA intact.

2. Performance – super call may be faster than virtual. super is implemented using invokespecial (single dispatch, just like private method), while ordinary call to non-private method uses double dispatch (virtual call). This is a weak advantage in modern JVMs.

Bottom line: if ClassB.execute() is final, using super has no sense.