12.10. throw Keyword

Try these first

1. 1.

   What is the purpose of the 'throw' keyword in Java?

   Hint

   Think about how you might signal that something has gone wrong in your program.

2. 2.

   Write a line of code using the 'throw' keyword to indicate a division by zero error.

   Hint

   Remember the exception type associated with arithmetic operations.

3. 3.

   What does the 'throw' keyword do in Java?

   • Creates a new method
   • Manually throws an exception
   • Handles an exception

   Hint

   It’s about signaling errors.

4. 4.

   True or False: The 'throw' keyword can be used in a method declaration.

   • True
   • False

   Hint

   Think about where you place the keywords.

5. 5.

   Design a simple application that prompts a user for their age and throws a custom exception if the age is less than a defined threshold (e.g., 18).

   Hint

   Think about how you’d communicate age restrictions.

6. 6.

   Write a method that calculates the square root of a number and throws an exception if the input number is negative.

   Hint

   What happens with negative numbers in square roots?