types of methods in java with code examples

Java is one of the most popular programming languages with an extensive range of applications in the computer industry. It is essential to master Java methods as they are integral to coding, functions, algorithms, and designing software systems. Java methods facilitate developers in breaking down complex programs into smaller, reusable components.

In this article, we will discuss the various types of methods in Java, including the syntax and implementation examples.

1. Static Methods
   Static methods in Java are the methods that can be accessed without creating an instance of the class it belongs to. These methods are declared using the keyword 'static.' Static methods are typically used to manipulate static variables or constants in a class.
   Syntax example:

public class MyClass{
   public static void myMethod(){
      // code to execute goes here
   }
}

2. Non-Static Methods
   Non-static methods in Java are the methods that can only be accessed by creating an instance of the object. These methods are declared without the keyword 'static.' Non-static methods are generally used to manipulate instance variables in a class.
   Syntax example:

public class MyClass{
   public void myMethod(){
      // code to execute goes here
   }
}

3. Abstract Methods
   Abstract methods in Java are methods that only have a declaration and no implementation. These methods are declared using the keyword 'abstract.' Abstract methods are typically used in abstract classes or interfaces, and their implementation is provided by the subclasses or implementing classes.
   Syntax example:

public abstract class MyAbstract{
   public abstract void myMethod();
}

4. Final Methods
   Final methods in Java are methods whose implementation cannot be overridden by the subclasses. These methods are declared using the keyword 'final.' Final methods are typically used to prevent the subclasses from modifying the behavior of the method.
   Syntax example:

public class MyClass{
   public final void myMethod(){
      // code to execute goes here
   }
}

5. Synchronized Methods
   Synchronized methods in Java are methods that can only be accessed by one thread at a time, ensuring thread safety. These methods are declared using the keyword 'synchronized.' Synchronized methods are generally used in multi-threaded applications to prevent concurrency issues.
   Syntax example:

public class MyClass{
   public synchronized void myMethod(){
      // code to execute goes here
   }
}

6. Private Methods
   Private methods in Java are methods that can only be accessed within the class it belongs to. These methods are declared using the keyword 'private.' Private methods are typically used to simplify code structure, encapsulate functionality, and increase security.
   Syntax example:

public class MyClass{
   private void myMethod(){
      // code to execute goes here
   }
}

7. Public Methods
   Public methods in Java are methods that can be accessed from anywhere within the program. These methods are declared using the keyword 'public.' Public methods are generally used for methods that need to be accessed globally and intended to be used by other classes.
   Syntax example:

public class MyClass{
   public void myMethod(){
      // code to execute goes here
   }
}

8. Instance Methods
   Instance methods in Java are methods that can only be accessed by an instance of the class. These methods operate on the instance variables of the class. Instance methods are widely used in object-oriented programming to define the behavior of an object.
   Syntax example:

public class MyClass{
   public void myMethod(){
      // code to execute goes here
   }
}

9. Native Methods
   Native methods in Java are methods that are implemented in a native language other than Java. These methods are declared using the keyword 'native.' Native methods are generally used to access hardware, operating system, and other third-party libraries that cannot be accessed using Java code.
   Syntax example:

public class MyNative{
   public native void myMethod() throws Exception;
}

In conclusion, Java methods are essential for designing and implementing software systems. As a Java developer, it is crucial to have a thorough understanding of each type of method and its implementation. Understanding these methods can help you write efficient and effective code while debug and tailoring for specific requirements.

1. Static Methods
   Static methods in Java can only access static variables or other static methods in a class. They do not have access to instance variables of an object. Static methods are called using the class name followed by the method name. For example:

MyClass.myMethod();

2. Non-Static Methods
   Non-static methods in Java can access instance variables and other non-static methods in a class. They require an instance of the class to be created to be called. Non-static methods are called using the object name followed by the method name. For example:

MyClass obj = new MyClass();
obj.myMethod();

3. Abstract Methods
   Abstract methods in Java do not have an implementation; they only have a declaration. Abstract methods are used in abstract classes or interfaces. When a class inherits an abstract method, it must provide its implementation. For example:

public abstract class MyAbstract {
   public abstract void myMethod();
}

4. Final Methods
   Final methods in Java cannot be overridden by the subclasses. It is useful when you want to prevent changes to the behavior of the method. Final methods are often used in the Template Method design pattern to prevent changes to the core algorithm of the method. For example:

public class MyClass {
   public final void myMethod() {
      // method code goes here
   }
}

5. Synchronized Methods
   Synchronized methods in Java ensure that only one thread can execute the method at a time. It is used to prevent multiple threads from accessing the same data simultaneously, causing inconsistencies. Synchronized methods can be time-consuming, so it is essential to use them only when necessary. For example:

public class MyClass {
   public synchronized void myMethod() {
      // method code goes here
   }
}

6. Private Methods
   Private methods in Java are accessible only within the class in which they are defined. It is used to encapsulate logic or implementation details that are not relevant to the outside world. Private methods can be called from other methods in the same class. For example:

public class MyClass {
   private void myMethod() {
      // method code goes here
   }
}

7. Public Methods
   Public methods in Java are accessible from anywhere in the program. It is used to expose functionality of a class to the outside world. Public methods are typically used when you want to access a method from another class. For example:

public class MyClass {
   public void myMethod() {
      // method code goes here
   }
}

8. Instance Methods
   Instance methods in Java operate on the instance variables of a class. It is called using an instance of the class. Instance methods are widely used in object-oriented programming to define the behavior of an object. For example:

public class MyClass {
    private int myVariable;

    public void setVar(int var){
        myVariable = var;
    }

    public void printVar(){
        System.out.println(myVariable);
    }
}

MyClass obj = new MyClass();
obj.setVar(10);
obj.printVar(); // Output: 10

9. Native Methods
   Native methods in Java are written in a language that is not Java, such as C or C++. Native methods are used to access system-level services or libraries that cannot be accessed using Java code. Native methods must be declared with the keyword 'native' and implemented in a different language. For example:

public class MyNative {
   public native void myMethod() throws Exception;
}

Popular questions

1. What is the difference between static and non-static methods in Java?
   Answer: Static methods can be accessed without creating an instance of the class it belongs to and can only manipulate static variables or constants in a class. Non-static methods require an instance of the object to be created to be called and can only manipulate instance variables in a class.

2. What is an abstract method in Java?
   Answer: An abstract method in Java is a method that only has a declaration and no implementation. Abstract methods are used in abstract classes or interfaces, and their implementation is provided by the subclasses or implementing classes.

3. What is a final method in Java?
   Answer: A final method in Java is a method whose implementation cannot be overridden by the subclasses. Final methods are typically used to prevent the subclasses from modifying the behavior of the method.

4. What is a synchronized method in Java?
   Answer: A synchronized method in Java is a method that can only be accessed by one thread at a time, ensuring thread safety. Synchronized methods are generally used in multi-threaded applications to prevent concurrency issues.

5. What is a native method in Java?
   Answer: A native method in Java is a method that is implemented in a native language other than Java, such as C or C++. Native methods are generally used to access hardware, operating systems, and other third-party libraries that cannot be accessed using Java code.

Tag

Java Methodology