extends

I am trying to understand extending inner classes in Java. I have read around but nothing I found quite answers my question. So here goes... I have... public class Pie{ protected Slice[] slices; // Pie constructor public Pie(int n){ sliceGenerator(n) } private void sliceGenerator(int n){ slices = new Slice[n]; final float sweepAngle = 360.0f/(float)n; float startAngle = 0; for (int i=0;i<n;i++){ slices[i] = new Slice(startAngle); startAngle += sweepAngle; } } @Override public String toString(){ for (Slice s:slices){ s.toString(); } } // Inner class... public class Slice{ public Slice(float

In Java type arguments, does mean strictly subtypes only? or would E also suffice? Yes, super and extends gives inclusive lower and upper bounds respectively. Here's a quote from Angelika Langer's Generics FAQ : What is a bounded wildcard? A wildcard with an upper bound looks like ? extends Type and stands for the family of all types that are subtypes of Type , type Type being included . Type is called the upper bound . A wildcard with a lower bound looks like ? super Type and stands for the family of all types that are supertypes of Type , type Type being included . Type is called the lower

This question already has answers here : Closed 8 years ago . Possible Duplicate: Can I extend a class using more than 1 class in PHP? I have a class that has several child classes, however I am now adding another class which I also want to be a child of the parent, however I would also like to utilize many of the functions from one of the other child classes. I've thought of just moving the respective functions from the other child class to the parent, however didn't think this was really needed as it would only be these two child classes that make use of them so was hoping that I could

when dealing with wildcards such as setting/adding a generic item to a certain container is it suggested to use something like this? void add(List<? super T> someList,someitem){ someList.add(someItem); } and when retrieving an item it is suggested to use something like this <T> void f1(List<? extends T> obj, T item) { obj.add(item); } What is the principle behind this? and when will I know if I should use this ? user1676688 you should have a look at the explanation of PECS principle What is PECS (Producer Extends Consumer Super)? In short, when you want to get information from an object, make

Trying out ES6 and tried to create a class with static properties and function for parsing. Then I want to extend the base parser for each different type I am parsing. Not sure if I am doing a anti-pattern but I cannot override static properties. This is my base parser class Module { static name = 'Default Module' static version = {major:10000, minor: 10000} static checkVersion({majorVersion = 10000, minorVersion = 10000}) { if(this.version.major !== majorVersion || this.version.minor > minorVersion) { throw `${this.name} requires version ${this.version.major}.${this.version.minor} got $

I have this code in a class that extends surface view and implements runnable I am able to use the class basically allows you to draw to the canvas using different colors and such. I'm trying to get a method that will allow me to save the image after it is drawn and this is the method. No matter what i do i just get a black image with nothing on it. Any ideas? I have cache drawing enabled Objective get a bitmap image from a custom SurfaceView I have exhausted options of looking at some other post on here and didn't find anything to work. Here is hoping that there is recently a new solution to

In java, say I have the following class: public class A{ protected class B{ } } can I extend the inner class by doing the following? public class C extends A{ protected class D extends B{ } } What I want to do is that I have the class C above and I need to change something in A's inner class so I was thinking that I need to extend the inner class to do so but I wasn't sure how exactly to do that. According to this page , you have the right way figured out to extend inner classes. A few tips about it can be found here , in the middle of the article (search for "extend"). If that doesn't work (I