Why is it important to create automated tests for code?

Automated tests are important because they:

• Allow quick verification that code changes haven't broken existing functionality.
• Accelerate the development process by reducing the number of bugs.
• Provide documentation of the code's behavior.
• Help during refactoring by giving confidence that the logic remains correct.

For example, by writing tests for a function that calculates the sum, you can quickly verify its correctness after changes.