Java Programming — Class Test | The British International School

A

Multiple Choice

25 marks

Choose the one correct answer. (1 mark each)

A1. Which Java keyword declares a constant? [1]

a) const b) final c) static d) constant

A2. In Java the first element of an array has index: [1]

a) 1 b) 0 c) −1 d) length

A3. Output of int[] arr={3,6,9,12}; System.out.println(arr[2]); [1]

a) 6 b) 9 c) 12 d) 3

A4. Which loop is guaranteed to run at least once? [1]

a) for b) while c) do...while d) if

A5. After int x = 7; x++; the value of x is: [1]

a) 6 b) 7 c) 8 d) 1

A6. Which operator returns the remainder of a division? [1]

a) / b) % c) * d) //

A7. Which method reads a line of input from a BufferedReader called br? [1]

a) br.nextInt() b) br.read() c) br.readLine() d) br.getLine()

A8. How many times does for(int i=1; i<=5; i++) repeat? [1]

a) 4 b) 5 c) 6 d) 1

A9. The logical AND operator in Java is: [1]

a) AND b) & c) && d) and

A10. For int[] nums={10,20,30,40};, nums.length is: [1]

a) 3 b) 4 c) 40 d) 0

A11. Which converts the String "25" into an int? [1]

a) Integer.parseInt("25") b) int("25") c) toInt("25") d) "25".int()

A12. Which line correctly creates a BufferedReader for keyboard input? [1]

a) new BufferedReader(new InputStreamReader(System.in)) b) new BufferedReader(System.in) c) new Scanner(System.in) d) new InputStreamReader()

A13. The method readLine() returns a value of type: [1]

a) int b) double c) String d) boolean

A14. Which import is needed to use BufferedReader? [1]

a) import java.math.*; b) import java.io.*; c) import java.array.*; d) import java.text.*;

A15. Which symbol means not equal to in Java? [1]

a) <> b) =/= c) != d) ==

A16. Which statement about a variable is correct? [1]

a) Its value may change while the program runs b) Its value can never change c) It must be written in capitals d) It cannot store numbers

A17. Output of int a=10, b=3; System.out.println(a % b); [1]

a) 3 b) 1 c) 0 d) 3.33

A18. Output of int a=10, b=3; System.out.println(a / b); [1]

a) 3 b) 3.33 c) 1 d) 4

A19. Which data type stores a whole number? [1]

a) double b) int c) char d) boolean

A20. Which data type is best for the value 3.14? [1]

a) int b) boolean c) double d) char

A21. The logical OR operator in Java is: [1]

a) OR b) | c) || d) or

A22. Which statement correctly performs totalling? [1]

a) sum = sum + num; b) sum = num; c) sum + num; d) sum == sum + num;

A23. Which statement correctly performs counting? [1]

a) count + 1; b) count == count + 1; c) count = 1; d) count = count + 1;

A24. Which symbol means greater than or equal to? [1]

a) => b) >= c) >> d) =<

A25. For int[] a={5,10,15}; the last valid index is: [1]

a) 3 b) 15 c) 2 d) 0

B

Match the Following

8 marks

Choose the correct meaning for each Java element. (1 mark each)

==

!=

final

%

.length

&&

||

while

C

True or False

10 marks

Decide whether each statement is true or false. (1 mark each)

D

Find the Error

16 marks

Each snippet has a mistake. State the error and the fix. (2 marks each)

D1. [2]

if (num % 2 = 0) {
    System.out.println("Even");
}

D2. [2]

int i = 1, n = 5;
while (i = n) {
    System.out.println(i);
    i +;
}

D3. [2]

int[] marks = {78, 85, 92};
System.out.println(marks[3]);

D4. [2]

BufferedReader br =
    new BufferedReader(new InputStreamReader(System.in));
int num = br.readLine();

D5. [2]

int[] data = {30, 65, 80};
int count = 0;
for (int i = 0; i < data.length; i++) {
    if (data[i] > 50)
        count + 1;
}
System.out.println(count);

D6. [2]

final int LIMIT = 50;
LIMIT = LIMIT + 10;
System.out.println(LIMIT);

D7. [2]

int[] a = {10, 20, 30};
for (int i = 0; i <= a.length; i++) {
    System.out.println(a[i]);
}

D8. [2]

int age = 20;
if (age >= 18) {
    System.out.println("Adult")
}

E

Correct the Code

16 marks

Rewrite each snippet so it works correctly. (4 marks each)

E1. Should display the numbers 1 to 5. [4]

int i = 1, n = 5;
while (i = n) {
    System.out.println(i);
    i +;
}

E2. Should print the total of all array elements. [4]

int[] arr = {4, 8, 15, 16, 23};
int sum;
for (int i = 1; i <= arr.length; i++) {
    sum = arr[i];
}
System.out.println("Sum: " + sum);

E3. Should count how many numbers are greater than 50. [4]

int[] data = {30, 65, 80, 20, 90};
int count;
for (int i = 0; i <= data.length; i++) {
    if (data[i] > 50) {
        count = count + 1
    }
}
System.out.println("Above 50: " + count);

E4. Should read two numbers and print their sum. [4]

BufferedReader br =
    new BufferedReader(new InputStreamReader(System.in));
int a = br.readLine();
int b = br.readLine();
int sum = a + b;
System.out.println(sum)

F

Programming Questions

25 marks

Write complete Java programs using BufferedReader br for input. (5 marks each)

F1. Write a program that reads five integers from the user into an array, displays them all using a loop, and finds and displays the largest value. [5]

F2. A worker enters the weight of each sack of rice; entering −1 stops the program. Write a program (condition-controlled loop) that counts the sacks and totals their weights, then outputs both. [5]

F3. Write a program that reads a number and states whether it is positive, negative or zero; if it is positive, it should also state whether it is even or odd (use nested selection). [5]

F4. Bank ATM Withdrawal System. Write a program that:
• takes the account balance and the withdrawal amount;
• checks if the balance is sufficient;
• if it is → deduct the amount and show the remaining balance;
• if it is not → show "Insufficient balance". [5]