Class is a Java class. Activity is a specific java class commonly used in Android. 1) Class is Blueprint of object and you will create as many object you want from same class. You can create new object by “new” keyword.
What is the difference between context and activity in Android?
2 Answers. An Application context lasts, as long as your app is alive, while the Activity context dies with your Activity (it is not valid after onDestroy of that Activity). So if you need the Context across Activities (i.e. in a Singleton) you will be better off using an Application context.
What is class and activity Android?
You implement an activity as a subclass of the Activity class. An activity provides the window in which the app draws its UI. This window typically fills the screen, but may be smaller than the screen and float on top of other windows. Generally, one activity implements one screen in an app.
Is activity a Java class?
An activity represents a single screen with a user interface just like window or frame of Java. Android activity is the subclass of ContextThemeWrapper class.
What is the use of context in Android?
It’s an abstract class whose implementation is provided by the Android system. Context allows access to application-specific resources and classes, as well as calls for application-level operations such as launching activities, broadcasting and receiving intents, etc.
What are the main two types of thread in Android?
Android has four basic types of threads. You’ll see other documentation talk about even more, but we’re going to focus on Thread , Handler , AsyncTask , and something called HandlerThread . You may have heard HandlerThread just called the “Handler/Looper combo”.
What is an anonymous class in Android?
It is an inner class without a name and for which only a single object is created. An anonymous inner class can be useful when making an instance of an object with certain “extras” such as overloading methods of a class or interface, without having to actually subclass a class.
What is singleton class in Android?
A singleton is a design pattern that restricts the instantiation of a class to only one instance. Notable uses include controlling concurrency and creating a central point of access for an application to access its data store. This example demonstrate about How to use singleton class in android.
What is a class index?
The class index indicates the target attribute used for classification. By default, in an ARFF file, it is the last attribute, which explains why it’s set to numAttributes-1. –