Exceptions in Lambda

In Java, exceptions can be thrown in lambda expressions just like in any other code. If a lambda expression throws an exception, it must be caught or declared in the same way as any other exception.

Here is an example of a lambda expression that throws an exception:

Runnable r = () -> {
  if (someCondition) {
    throw new MyException("Some error message");
  }
  // other code
};

In this example, the lambda expression throws a MyException if the someCondition is true.

If the lambda expression is used in a context where the exception must be caught or declared, it can be handled in the same way as any other exception. For example, if the lambda expression is used in a try-catch block, the exception can be caught and handled:

try {
  r.run();
} catch (MyException e) {
  // handle the exception
}

Alternatively, if the lambda expression is used in a context where the exception must be declared, it can be declared in the same way as any other exception:

public void someMethod() throws MyException {
  r.run();
  // other code
}

It's worth noting that the type of exception that can be thrown by a lambda expression is determined by the functional interface that the lambda expression is implementing. For example, if the lambda expression is implementing the Runnable interface, it can throw any exception that is allowed by the run() method of the Runnable interface.

It's also worth noting that some functional interfaces, such as Function, have multiple abstract methods, and in these cases, the lambda expression can throw any exception that is allowed by any of the abstract methods of the interface.