What is the reason of using ? extends anyobject in case of Interface.

Question

My Question is this, why we use "extends" instead of "implements"

Answer 1

If you have a look at a programming manual for C#, you'll see that the "extends" relationship, that in java would be written "class Child extends Parent", is written as "class Child : Parent".
If you look farther, you'll see that the "implements" relationship, that in java would be "class Child implements IChild", is written as "class Child : IChild".
It turns out that putting the keyword "interface" or "class" on the parent entity is enough for the compiler to figure it out. (Duh!) It also turns out that all those people who have been droning on and on about "Don't name your interfaces with a leading I, because if you change them to abstract base classes you'll have to edit the code to fix it" had apparently forgotten that if you change "implements" to "extends" you've already edited the code.
So I don't actually know why, but I'd guess that someone in Java-land had a sudden flow of oxygenated blood to the brain, and realized that having two keywords would require them to implement a lot of tracking and parsing and whatnot for essentially zero return.
Sure, it's inconsistent with the rest of the language. But it leaves hope that Java 7 or 8 will make the "implements" and "extends" keywords interchangeable, at least in one direction.
=Austin