Java interview programming questions 

Programs – Category A:

1. Write a program to accept two numbers from the user and find their sum and average.
2. Write a program to accept a number from the user and find the cube of that number (to the power 3).
3. Write a program to find the simple interest based on the following data: P = Rs 6000, R = 10%, T = 1.5 years.
4. Write a program to accept two numbers from the user and swap their values. (Example: x=12, y=15; after swapping x=15, y=12)
5. Write a program to accept the weight of 5 persons (one by one) and display the net weight and the average weight.

Programs on “If” statement:

1. Write a program to accept a number from the user. If the number is negative then convert it to a positive number and print; if it is a positive number, print it as is.
2. Write a program to accept the bill amount and age of the customer; if the customer’s age is >50 years then give a discount of 5% on the bill.
3. Write a program to accept a number and find whether it is even or odd.
4. Write a program to accept two numbers from the user and find the bigger of the two.
5. Write a program to accept three numbers and find the biggest number.
6. If cost price and selling price of an item is input through the keyboard, write a program to determine whether the seller has made a profit or incurred a loss. Also determine the quantum of profit or loss.
7. Write a program to accept any character from the user; determine whether it is – a letter in the upper case, lower case, digit, or a special symbol. (Hint: Use ASCII values.)

Programs on “Iterative” statement:

8. Write a program to accept a number from the user and print its multiplication table (upto “times 10”).

9. Write a program to accept a number and find the factorial of the number.

10. Write a program to accept a number,calculate the sum of all even numbers from 0 till the given number; similarly repeat the same for the odd numbers; then display these two sums. (Example: input number 6; sum of even numbers = 0+2+4+6 =12, sum of odd numbers = 1+3+5 = 9)

11. Write a program to accept a number from the user; display the natural number series for the entered number (1,2,3,4,…,N) and calculate the sum of this series.

12. Write a program to accept a number and determine whether it is a prime number or not.

13. Write a program to print the Fibonacci series up to the number 34. (Example: 0,1,1,2,3,5,8,13,…Series starts with 0 and 1, the succeeding numbers of the series are arrived by adding the previous 2 numbers.)

14. Write a program to accept a number “n” from the user; then display the sum of the series 1+1/2+1/3+……….+1/n.

15. Write a program to accept a number “n” from the user; then display the series 1,3,5,7,9,…,n and find the sum of the numbers in this series.

16. Write a program to accept 2 different numbers from the user and print the prime numbers between these 2 numbers.

17. Write a program to print the following output.

1

2 3

4 5 6 7

8 9 10 11

18. Write a program to print the following output.

*

* *

* * *

* * * *

* * * * *

19. Write a program to print the following output.

                         *

                         * * *

                         * * * * *

                         * * * * * * *

                         * * * * * * * * *

20. Write a program to print the following output.

                             1

                             121

12321

1234321

123454321

21. Write a program to print the following output.

                    19 0 0

                    0 19 0

                    0 0 19

22. Write a program to accept a number “n” from the user; find the sum of the series 1/2³+1/3³+1/4³……..+1/n³.

Programs on “Iterative” statement:

24. Write a program to accept a number from the user and count the number of digits in the number.
25. Write a program to accept a number from the user and find the sum of digits in the given number.

25. Write a program to accept a number from the user and find the reverse of the given number.

26. Write a program to accept a number from the user and determine whether it is an Armstrong number or not (Example : 153 is Armstrong 1^3 + 5 ^3 +3 ^3 =153)

27. Write a program to accept a number from the user and find the sum of digits of the number; repeat the operation till the sum gets to be a single digit number.

28. Write a program to accept a number from the user and find the count of the digits that are prime numbers.

29. Write a program to accept a number and find the factorial of the number (using while loop).

30. Write a program to accept a four digit number from the user and display its denomination.

Example: 5698

Output: 5*1000 =5000

6*100 =600

9*10 =90

8*1 =8

31. Write a program to accept a five digit number and increment each digit by one and display the number (digit 9 gets incremented to 0).

Example:

     Input: 14385

Output: 25496

32. Write a program to accept 2 numbers “m” and “n” from the user and determine m^n (without using predefined functions).