Overview of Nested, Static, Anonymous, Local Inner Classes

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1. Constructors </aside>

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1. Methods in Java </aside>

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1. Static Keyword </aside>

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1. Static Methods </aside>

Constructors in Java

1. Constructors

   1. Definition

      1. A constructor is a special method in Java used to initialize objects. It is invoked automatically when an object of a class is created.

   2. Key Characteristics

      1. The name of the constructor must match the class name.
      2. It does not have a return type (not even void).
      3. Used to initialize object properties.

   3. Types of Constructors

      1. Default Constructor: Automatically provided by Java if no constructors are explicitly defined.
      2. Parameterized Constructor: Accepts parameters to initialize object properties.
      3. No-argument Constructor: A constructor with no parameters.

   4. Example: Default Constructor

      class Vehicle {
          Vehicle() { // Default constructor
              System.out.println("Vehicle created.");
          }
      }
      
      public class Main {
          public static void main(String[] args) {
              Vehicle v = new Vehicle(); // Constructor called
          }
      }
      

   5. Output:

      Vehicle created.
      

   6. Example: Parameterized Constructor

      class Vehicle {
          String name;
      
          Vehicle(String name) { // Parameterized constructor
              this.name = name;
          }
      
          void display() {
              System.out.println("Vehicle Name: " + name);
          }
      }
      
      public class Main {
          public static void main(String[] args) {
              Vehicle car = new Vehicle("Car");
              car.display();
          }
      }
      

   7. Output:

      Vehicle Name: Car