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Author: Nafiz

Protocol in Swift
Protocol in Swift

In Swift, a protocol defines a blueprint of methods, properties, and other requirements that suit a particular task or piece of functionality. The protocol can then be adopted by a class, structure, or enumeration to provide an actual implementation of those requirements. Any type that satisfies the requirements of a protocol is said to conform to that protocol.

Protocols are a way to define a set of requirements for any type to conform to. This means that you can use protocols to define the expected behavior for a particular task or piece of functionality, without worrying about how that functionality will be implemented. This makes it easy to write flexible and reusable code that can be used in a variety of contexts.

For example, if you were creating a game, you might define a protocol called “Level” that specifies the properties and methods that all levels in the game must have. Then, any class that adopts the Level protocol must implement those properties and methods, so that they can be used in the game.

Here is an example of how a protocol might be defined in Swift:
```
protocol Level {
    var name: String { get set }
    func complete()
    func start()
}
```
In this example, the Level protocol defines two properties (name and difficulty) and two methods (complete and start). Any type that adopts the Level protocol must implement these properties and methods, so that it can be used in the game.

To adopt a protocol, you write the protocol’s name after the class name, separated by a colon. Here is an example of how a class might adopt the Level protocol from the previous example:
```
class ForestLevel: Level {
    var name: String = "Forest"
    var difficulty: Int = 3

    func complete() {
        print("You have completed the Forest level!")
    }

    func start() {
        print("Starting the Forest level...")
    }
}
```
In this example, the ForestLevel class adopts the Level protocol and provides an implementation of its requirements. This means that the ForestLevel class can be used as a level in the game, and it will have the properties and methods specified by the Level protocol.

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June 11, 2022
Create Notification on Android in Java
Create Notification on Android in Java

To create a notification on Android in Java, you can use the NotificationCompat.Builder class and its setContentTitle(), setContentText(), and setSmallIcon() methods to set the title, text, and icon for the notification, respectively. You can then use the getNotification() method to retrieve the notification object, and the notify() method of the NotificationManager class to post the notification.

Here is an example of how you could create and post a notification in Java on Android:
```
// Create the NotificationCompat.Builder object
NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
        .setContentTitle("Notification Title")
        .setContentText("This is the notification text.")
        .setSmallIcon(R.drawable.notification_icon);

// Get the Notification object
Notification notification = builder.build();

// Get the NotificationManager and post the notification
NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
manager.notify(NOTIFICATION_ID, notification);
```
This code will create a notification with the specified title and text, and using the icon specified by the notification_icon drawable resource. When the notification is posted, it will be assigned the ID specified by the NOTIFICATION_ID constant.

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April 23, 2022
Java Factory Design Pattern
Java Factory Design Pattern

The factory design pattern is a common design pattern used in software development, particularly in object-oriented programming languages like Java. The factory design pattern is a creational design pattern, which means that it deals with object creation.

The factory design pattern is a way to provide a common interface for creating objects without specifying the exact class of object that will be created. This allows the code that uses the objects to be independent of the specific implementation of the objects.

Here is an example of how the factory design pattern might be implemented in Java:
```
public interface Shape {
  void draw();
}

public class Circle implements Shape {
  @Override
  public void draw() {
    // code to draw a circle
  }
}

public class Rectangle implements Shape {
  @Override
  public void draw() {
    // code to draw a rectangle
  }
}

public class ShapeFactory {
  public static Shape getShape(String shapeType) {
    if (shapeType == null) {
      return null;
    }
    if (shapeType.equalsIgnoreCase("CIRCLE")) {
      return new Circle();
    } else if (shapeType.equalsIgnoreCase("RECTANGLE")) {
      return new Rectangle();
    }
    return null;
  }
}
```
In the example above, the ShapeFactory class provides a static method called getShape() that takes a shapeType as an input and returns an object of the specified Shape type. This allows the code that uses the ShapeFactory to create Shape objects without knowing the exact implementation of the objects.

The factory design pattern is a useful pattern to use in Java because it promotes loose coupling and code reuse. It allows you to create objects without specifying their exact class, which makes your code more flexible and easier to maintain.

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March 23, 2022