Error handling

Question 1

What is the role of the try block in error handling?

a) To catch errors and prevent program execution
b) To handle exceptions only if they occur
c) To run the code that might cause an exception
d) To define a safe area in the code

Answer 1

c) To run the code that might cause an exception

Question 2

When the parseInt method fails to convert a string to an integer, what exception is thrown?

a) NullPointerException
b) ArithmeticException
c) InputMismatchException
d) NumberFormatException

Answer 2

d) NumberFormatException

Question 3

In the code catch (Exception ex), what is the purpose of catching the base Exception?

a) To catch all possible exceptions
b) To ignore all exceptions
c) To handle only runtime errors
d) To handle specific exceptions

Answer 3

a) To catch all possible exceptions

Question 4

What is the purpose of adding multiple catch clauses in a try-catch block?

a) To handle different exceptions with different responses
b) To handle the same exception multiple times
c) To improve performance
d) To avoid handling exceptions

Answer 4

a) To handle different exceptions with different responses

Question 5

What does the condition if (number > 31 && number < 256) check?

a) Whether the number is within the printable ASCII range
b) Whether the number is a valid integer
c) Whether the number equals 31 or 256
d) Whether the number is less than 31 or greater than 256

Answer 5

a) Whether the number is within the printable ASCII range

Question 6

In the if statement, what does the double ampersand && represent?

a) OR logic
b) XOR logic
c) AND logic
d) NOT logic

Answer 6

c) AND logic

Question 7

In Java, what is the correct name for a structure that checks multiple cases based on one variable?

a) if/else structure
b) switch/case statement
c) for loop
d) try/catch block

Answer 7

b) switch/case statement

Question 8

What is the purpose of the break statement inside a switch/case structure?

a) To exit the program
b) To exit the loop
c) To terminate the switch/case block
d) To skip a case

Answer 8

c) To terminate the switch/case block

Question 9

In the switch/case structure, what happens if the break statement is missing after a case?

a) The program crashes
b) The next case will automatically be executed
c) The switch statement will stop
d) The code execution will stop

Answer 9

b) The next case will automatically be executed

Question 10

Why do we add a default case to a switch/case statement?

a) To handle unexpected cases
b) To increase performance
c) To skip certain cases
d) To avoid the use of break statements

Answer 10

a) To handle unexpected cases

Question 11

Which loop would you use to ensure that the code runs at least once?

a) for loop
b) while loop
c) do loop
d) switch loop

Answer 11

c) do loop

Question 12

What is the purpose of using random.nextInt(5) + 1 in the RandomCase program?

a) To generate a random number between 1 and 5
b) To generate a random number between 0 and 5
c) To generate only even numbers
d) To generate a random number between 0 and 1

Answer 12

a) To generate a random number between 1 and 5

Question 13

What will the following code output if rndNumber is 3?

switch(rndNumber) {  
case 1: System.out.println("One"); break;  
case 2: System.out.println("Two"); break;  
case 3: System.out.println("Three"); break;  
}

a) Two
b) Three
c) One
d) Nothing

Answer 13

b) Three

Question 14

What type of loop is used to repeat code until a specified condition is met?

a) do loop
b) while loop
c) for loop
d) switch loop

Answer 14

b) while loop

Question 15

What is the potential risk of forgetting to set a condition to true inside a while loop?

a) The program will not compile
b) The program will enter an infinite loop
c) The program will skip the loop
d) The program will break after the first iteration

Answer 15

b) The program will enter an infinite loop

Question 16

What is the key difference between a for loop and a while loop?

a) A for loop repeats indefinitely
b) A while loop checks the condition before the loop starts
c) A for loop runs until a condition becomes false
d) A while loop runs at least once

Answer 16

b) A while loop checks the condition before the loop starts

Question 17

What output will this loop produce if fourFound is set to true at the beginning?

do {  
    int rndNumber = random.nextInt(5) + 1;  
    switch(rndNumber) {  
        case 1: System.out.println("One"); break;  
        case 4: System.out.println("Four"); break;  
    }  
} while (!fourFound);

a) The loop runs infinitely
b) The loop prints a random number
c) The loop runs once and prints a number
d) The loop prints nothing

Answer 17

c) The loop runs once and prints a number