What is the Difference Between throw and throws in Java?

The 'throw' and 'throws' keywords in Java are used in the context of exception handling but serve different purposes and are used in different scenarios. Here are the main differences between them:

1. Usage:

• 'throw' is used to explicitly throw an exception from within a block of code or a method.
• 'throws' is used in a method signature to declare the exceptions that a method can potentially throw.

1. Exception Type:

• 'throw' can only propagate unchecked exceptions.
• 'throws' can declare both unchecked and checked exceptions.

1. Syntax:

• The instance variable follows the 'throw' keyword.
• The exception class names follow the 'throws' keyword.

1. Exception Throwing:

• The 'throw' keyword is used to throw an exception explicitly.
• The 'throws' keyword declares which exceptions can be thrown by a method, allowing other methods to catch or handle them.

1. Exception Handling:

• Using 'throw' allows you to handle exceptions based on certain conditions within a code block.
• Using 'throws' allows exception propagation, where an exception propagates from method to method, up the call stack, until it's caught.

In summary, 'throw' is used to explicitly throw an exception within a method or block of code, while 'throws' is used in a method signature to declare potential exceptions that can be thrown by the method. 'throw' can only propagate unchecked exceptions, while 'throws' can declare both unchecked and checked exceptions.

Comparative Table: throw vs throws in Java

Here is a table highlighting the differences between throw and throws in Java:

In summary, throws is used to declare the exceptions that a method might throw, while throw is used to explicitly throw an exception within a method or block of code. The throws keyword is used in the method declaration, while the throw keyword is used inside the method body. The throw keyword can throw only one exception at a time, while the throws keyword can declare multiple exceptions. Additionally, the throws keyword is used to propagate both checked and unchecked exceptions, while the throw keyword propagates only unchecked exceptions.