Unit 7: Exeptions

Question 1

What is an “exception” in Java?

Answer 1

An event that occurs during the execution of a program that disrupts the normal flow, like a file not found or invalid number input.

Question 2

Give examples of common exceptions in Java.

Answer 2

FileNotFoundException

ArrayIndexOutOfBoundsException

NumberFormatException

Question 3

What happens if an exception is not handled?

Answer 3

The JVM reports the exception and skips to the next event — the program may miss actions or become unreliable.

Question 4

Why should we handle exceptions instead of ignoring them?

Answer 4

To avoid crashes, ugly error messages, or continuing with unreliable/partial data — important in professional software.

Question 5

What is the basic structure for handling exceptions in Java?

Answer 5

try {
// risky code
} catch (ExceptionType e) {
// handle it
}

Question 6

When does the catch block run?

Answer 6

Only if an exception is thrown in the try block — otherwise, it’s skipped.

Question 7

Why not always check for errors before running risky code?

Answer 7

Sometimes it’s hard or impossible to predict if an error will happen — using try-catch is more reliable.