Purpose:

• The throw keyword is used to explicitly create and throw an exception. It is primarily used to hand over a custom or user-defined exception object to the JVM.
• It can be used to throw both checked and unchecked exceptions.
• After the throw statement, no code should be placed because it will result in a compile-time error; the flow of execution immediately stops and control is passed to the nearest catch block.

Usage:

• The throw keyword is used when you want to manually trigger an exception based on certain conditions or business logic.
• Common use cases include input validation, enforcing business rules, or throwing custom exceptions to provide more context for an error.

Advantages:

• Manual Control: Allows developers to manually trigger exceptions based on specific conditions.
• Custom Exception Handling: Facilitates the creation of custom exceptions, enabling more descriptive error messages and better error handling.
• Enforce Business Rules: Ensures that certain business rules are adhered to within the application.

Disadvantages:

• Code Interruption: The flow of the code is interrupted, which may require more careful handling to ensure the application can recover from the exception.

Purpose:

• The throws keyword is used in the method signature to declare that a method might throw one or more exceptions. It delegates the responsibility of handling the exception to the method's caller.
• It is primarily used for checked exceptions, which the compiler requires to be either caught or declared in the method signature.

Usage:

• The throws keyword is used when a method is not intended to handle an exception but wants to signal to the caller that an exception might occur.
• It is recommended to use try-catch for handling exceptions rather than just declaring them with throws, as throws does not prevent abnormal program termination.

Syntax:

public void methodName() throws ExceptionType1, ExceptionType2 {
    // Method body
}

Key Points:

• Delegation of Responsibility: The throws keyword delegates the responsibility of exception handling to the method that calls it.
• Checked Exceptions: Primarily used for checked exceptions, ensuring the caller is aware and handles the potential exceptions.
• Method Signature: Only declared in the method signature; it does not handle the exception itself.
• Method and Constructor Use: The throws keyword can be used with both methods and constructors but not with classes.

Advantages:

• Clarity: Makes it clear in the method signature what exceptions might be thrown, improving code readability and maintainability.
• Flexible Exception Handling: Allows exceptions to be handled at higher levels of the code, providing flexibility in how exceptions are managed.

Disadvantages:

• Potential for Unhandled Exceptions: If the caller does not handle the declared exceptions, it could lead to program termination.
• Less Control: Developers may lose control over how exceptions are handled if they are simply declared rather than caught and managed.