Practice 100 Java Basic Part II Programming Questions

Practice 100 Java Basic Part II Programming Questions

Q1. Write a Java program to calculate the square of a given number.  
Input:  
Enter a number: 7

Expected Output:  
Square = 49

Q2. Write a Java program to swap two numbers using a temporary variable.  
Input:  
Enter first number: 10  
Enter second number: 20

Expected Output:  
After swapping:  
First number = 20  
Second number = 10

Q3. Write a Java program to calculate the area of a triangle using its base and height.  
Input:  
Enter base: 5  
Enter height: 10

Expected Output:  
Area of the triangle = 25.0

Q4. Write a Java program to check if a given year is a leap year.  
Input:  
Enter a year: 2024

Expected Output:  
2024 is a leap year.

Q5. Write a Java program to reverse a number.  
Input:  
Enter a number: 12345

Expected Output:  
Reversed number = 54321

Q6. Write a Java program to calculate the sum of digits of a given number.  
Input:  
Enter a number: 456

Expected Output:  
Sum of digits = 15

Q7. Write a Java program to display all even numbers up to a given number.  
Input:  
Enter the limit: 10

Expected Output:  
Even numbers: 2 4 6 8 10

Q8. Write a Java program to check if a number is positive, negative, or zero.  
Input:  
Enter a number: -5

Expected Output:  
The number is negative.

Q9. Write a Java program to find the largest of three numbers.  
Input:  
Enter three numbers: 12 45 30

Expected Output:  
The largest number is 45.

Q10. Write a Java program to calculate the perimeter of a rectangle.  
Input:  
Enter length: 8  
Enter width: 5

Expected Output:  
Perimeter of the rectangle = 26

Q11. Write a Java program to find the ASCII value of a character.  
Input:  
Enter a character: A

Expected Output:  
ASCII value of A = 65

Q12. Write a Java program to count the number of vowels in a string.  
Input:  
Enter a string: Hello World

Expected Output:  
Number of vowels = 3

Q13. Write a Java program to print a multiplication table for a given number.  
Input:  
Enter a number: 5

Expected Output:  
5 x 1 = 5  
5 x 2 = 10  
...  
5 x 10 = 50

Q14. Write a Java program to find the sum of an array of integers.  
Input:  
Enter array elements: 1 2 3 4 5

Expected Output:  
Sum = 15

Q15. Write a Java program to reverse a string.  
Input:  
Enter a string: Java

Expected Output:  
Reversed string = avaJ

Q16. Write a Java program to check if a character is a vowel or a consonant.  
Input:  
Enter a character: e

Expected Output:  
e is a vowel.

Q17. Write a Java program to find the second largest number in an array.  
Input:  
Enter array elements: 10 20 30 40 50

Expected Output:  
Second largest number = 40

Q18. Write a Java program to calculate the simple interest.  
Input:  
Enter principal: 1000  
Enter rate: 5  
Enter time: 2

Expected Output:  
Simple interest = 100

Q19. Write a Java program to check if a string contains only digits.  
Input:  
Enter a string: 12345

Expected Output:  
The string contains only digits.

Q20. Write a Java program to find the greatest common divisor (GCD) of two numbers.  
Input:  
Enter two numbers: 12 15

Expected Output:  
GCD = 3

Q21. Write a Java program to convert a binary number to a decimal number.  
Input:  
Enter a binary number: 1010

Expected Output:  
Decimal equivalent = 10

Q22. Write a Java program to convert a decimal number to a binary number.  
Input:  
Enter a decimal number: 15

Expected Output:  
Binary equivalent = 1111

Q23. Write a Java program to count the number of words in a string.  
Input:  
Enter a string: Java is fun

Expected Output:  
Number of words = 3

Q24. Write a Java program to find the smallest element in an array.  
Input:  
Enter array elements: 10 20 5 30

Expected Output:  
Smallest element = 5

Q25. Write a Java program to calculate the average of an array of integers.  
Input:  
Enter array elements: 2 4 6 8 10

Expected Output:  
Average = 6.0

Q26. Write a Java program to check if a number is divisible by both 3 and 5.  
Input:  
Enter a number: 15

Expected Output:  
15 is divisible by both 3 and 5.

Q27. Write a Java program to calculate the power of a number using a loop.  
Input:  
Enter base: 2  
Enter exponent: 3

Expected Output:  
Result = 8

Q28. Write a Java program to calculate the compound interest.  
Input:  
Enter principal: 1000  
Enter rate: 5  
Enter time: 2  
Enter number of times interest applied per time: 2

Expected Output:  
Compound interest = 1102.5

Q29. Write a Java program to check if an array is sorted in ascending order.  
Input:  
Enter array elements: 1 2 3 4 5

Expected Output:  
The array is sorted in ascending order.

Q30. Write a Java program to calculate the sum of even and odd numbers separately in a given range.  
Input:  
Enter start: 1  
Enter end: 10

Expected Output:  
Sum of even numbers = 30  
Sum of odd numbers = 25

Q31. Write a Java program to find the factorial of a number using a loop.  
Input:  
Enter a number: 5

Expected Output:  
Factorial = 120

Q32. Write a Java program to print the Fibonacci series up to a given number of terms.  
Input:  
Enter number of terms: 7

Expected Output:  
Fibonacci series: 0 1 1 2 3 5 8

Q33. Write a Java program to check if a given string is a palindrome.  
Input:  
Enter a string: madam

Expected Output:  
The string is a palindrome.

Q34. Write a Java program to calculate the product of digits of a given number.  
Input:  
Enter a number: 123

Expected Output:  
Product of digits = 6

Q35. Write a Java program to check if a number is a perfect square.  
Input:  
Enter a number: 16

Expected Output:  
16 is a perfect square.

Q36. Write a Java program to count the number of occurrences of a character in a string.  
Input:  
Enter a string: programming  
Enter a character: g

Expected Output:  
The character 'g' appears 2 times.

Q37. Write a Java program to check if two strings are anagrams of each other.  
Input:  
Enter first string: listen  
Enter second string: silent

Expected Output:  
The strings are anagrams.

Q38. Write a Java program to remove all spaces from a string.  
Input:  
Enter a string: Hello World

Expected Output:  
String without spaces: HelloWorld

Q39. Write a Java program to calculate the sum of squares of the first N natural numbers.  
Input:  
Enter a number: 3

Expected Output:  
Sum of squares = 14

Q40. Write a Java program to generate the first N prime numbers.  
Input:  
Enter N: 5

Expected Output:  
First 5 prime numbers: 2 3 5 7 11

Q41. Write a Java program to check if a number is an Armstrong number.  
Input:  
Enter a number: 153

Expected Output:  
153 is an Armstrong number.

Q42. Write a Java program to check if a number is a palindrome.  
Input:  
Enter a number: 121

Expected Output:  
The number is a palindrome.

Q43. Write a Java program to calculate the LCM of two numbers.  
Input:  
Enter two numbers: 12 15

Expected Output:  
LCM = 60

Q44. Write a Java program to sort an array of strings in alphabetical order.  
Input:  
Enter strings: apple banana cherry

Expected Output:  
Sorted strings: apple banana cherry

Q45. Write a Java program to find the length of the longest word in a string.  
Input:  
Enter a string: Java programming language

Expected Output:  
The longest word is 'programming' with length 11.

Q46. Write a Java program to find the sum of diagonal elements of a 2D matrix.  
Input:  
Enter 2D matrix:  
1 2 3  
4 5 6  
7 8 9

Expected Output:  
Sum of diagonal elements = 15

Q47. Write a Java program to print the transpose of a 2D matrix.  
Input:  
Enter 2D matrix:  
1 2  
3 4  
5 6

Expected Output:  
Transpose:  
1 3 5  
2 4 6

Q48. Write a Java program to find the mode of an array of integers.  
Input:  
Enter array elements: 2 3 2 4 5 2

Expected Output:  
Mode = 2

Q49. Write a Java program to find the frequency of elements in an array.  
Input:  
Enter array elements: 1 2 2 3 3 3

Expected Output:  
Element: 1 Frequency: 1  
Element: 2 Frequency: 2  
Element: 3 Frequency: 3

Q50. Write a Java program to find all prime factors of a number.  
Input:  
Enter a number: 28

Expected Output:  
Prime factors: 2 2 7

Q51. Write a Java program to find the sum of odd numbers in a given range.  
Input:  
Enter start: 1  
Enter end: 10

Expected Output:  
Sum of odd numbers = 25

Q52. Write a Java program to calculate the GCD of two numbers using recursion.  
Input:  
Enter two numbers: 48 18

Expected Output:  
GCD = 6

Q53. Write a Java program to check if a number is a power of 2.  
Input:  
Enter a number: 16

Expected Output:  
16 is a power of 2.

Q54. Write a Java program to print the prime numbers up to N.  
Input:  
Enter N: 10

Expected Output:  
Prime numbers up to 10: 2 3 5 7

Q55. Write a Java program to reverse an integer.  
Input:  
Enter a number: 12345

Expected Output:  
Reversed number = 54321

Q56. Write a Java program to find the square root of a number.  
Input:  
Enter a number: 25

Expected Output:  
Square root = 5.0

Q57. Write a Java program to print the pattern of stars in a triangle shape.  
Input:  
Enter number of rows: 5

Expected Output:  
*  
**  
***  
****  
*****

Q58. Write a Java program to find the frequency of vowels in a string.  
Input:  
Enter a string: Hello World

Expected Output:  
Vowels frequency: 3

Q59. Write a Java program to find the area of a rectangle.  
Input:  
Enter length: 10  
Enter width: 5

Expected Output:  
Area = 50

Q60. Write a Java program to convert temperature from Celsius to Fahrenheit.  
Input:  
Enter temperature in Celsius: 25

Expected Output:  
Temperature in Fahrenheit = 77.0

Q61. Write a Java program to print the Fibonacci series up to N terms using recursion.  
Input:  
Enter number of terms: 6

Expected Output:  
Fibonacci series: 0 1 1 2 3 5

Q62. Write a Java program to find the sum of digits of a number.  
Input:  
Enter a number: 123

Expected Output:  
Sum of digits = 6

Q63. Write a Java program to generate the Pascal’s Triangle.  
Input:  
Enter number of rows: 5

Expected Output:  
   1  
  1 1  
 1 2 1  
1 3 3 1  
1 4 6 4 1

Q64. Write a Java program to swap two numbers using a temporary variable.  
Input:  
Enter first number: 5  
Enter second number: 10

Expected Output:  
After swapping: first number = 10, second number = 5

Q65. Write a Java program to find the largest element in an array.  
Input:  
Enter array elements: 5 10 15 20

Expected Output:  
Largest element = 20

Q66. Write a Java program to calculate the sum of cubes of first N natural numbers.  
Input:  
Enter N: 3

Expected Output:  
Sum of cubes = 36

Q67. Write a Java program to find the sum of even numbers in a given range.  
Input:  
Enter start: 1  
Enter end: 10

Expected Output:  
Sum of even numbers = 30

Q68. Write a Java program to remove duplicate elements from an array.  
Input:  
Enter array elements: 1 2 2 3 4 4 5

Expected Output:  
Array without duplicates: 1 2 3 4 5

Q69. Write a Java program to check if a number is prime.  
Input:  
Enter a number: 13

Expected Output:  
13 is a prime number.

Q70. Write a Java program to print all the prime numbers up to N using a for loop.  
Input:  
Enter N: 20

Expected Output:  
Prime numbers up to 20: 2 3 5 7 11 13 17 19

Q71. Write a Java program to find the reverse of a string without using any library functions.  
Input:  
Enter a string: Java

Expected Output:  
Reversed string = avaJ

Q72. Write a Java program to check if a string is a valid number (integer or decimal).  
Input:  
Enter a string: 12.34

Expected Output:  
The string is a valid number.

Q73. Write a Java program to calculate the perimeter of a rectangle.  
Input:  
Enter length: 10  
Enter width: 5

Expected Output:  
Perimeter = 30

Q74. Write a Java program to find the sum of elements in the main diagonal of a matrix.  
Input:  
Enter matrix elements:  
1 2 3  
4 5 6  
7 8 9

Expected Output:  
Sum of diagonal elements = 15

Q75. Write a Java program to check if a number is divisible by 7 but not 5.  
Input:  
Enter a number: 14

Expected Output:  
14 is divisible by 7 but not by 5.

Q76. Write a Java program to count the number of even and odd digits in a number.  
Input:  
Enter a number: 12345

Expected Output:  
Even digits = 2, Odd digits = 3

Q77. Write a Java program to check if a number is a perfect number.  
Input:  
Enter a number: 28

Expected Output:  
28 is a perfect number.

Q78. Write a Java program to print the sum of two 2D matrices.  
Input:  
Enter first matrix:  
1 2 3  
4 5 6  
Enter second matrix:  
7 8 9  
10 11 12

Expected Output:  
Sum of matrices:  
8 10 12  
14 16 18

Q79. Write a Java program to calculate the area of a circle.  
Input:  
Enter radius: 7

Expected Output:  
Area = 153.94

Q80. Write a Java program to find the second smallest number in an array.  
Input:  
Enter array elements: 10 20 30 5 15

Expected Output:  
Second smallest number = 10

Q81. Write a Java program to check if a number is an abundant number.  
Input:  
Enter a number: 12

Expected Output:  
12 is an abundant number.

Q82. Write a Java program to find the sum of squares of the even numbers in a given range.  
Input:  
Enter start: 1  
Enter end: 10

Expected Output:  
Sum of squares of even numbers = 220

Q83. Write a Java program to check if a number is a strong number.  
Input:  
Enter a number: 145

Expected Output:  
145 is a strong number.

Q84. Write a Java program to remove the first occurrence of a character in a string.  
Input:  
Enter a string: programming  
Enter character to remove: r

Expected Output:  
String after removal: pogramming

Q85. Write a Java program to find the number of prime numbers in a given range.  
Input:  
Enter start: 1  
Enter end: 10

Expected Output:  
Number of primes = 4

Q86. Write a Java program to check if a number is an odd number.  
Input:  
Enter a number: 7

Expected Output:  
7 is an odd number.

Q87. Write a Java program to print the multiplication table of a given number.  
Input:  
Enter a number: 5

Expected Output:  
5 x 1 = 5  
5 x 2 = 10  
5 x 3 = 15  
...  
5 x 10 = 50

Q88. Write a Java program to calculate the square of a number using a function.  
Input:  
Enter a number: 4

Expected Output:  
Square = 16

Q89. Write a Java program to swap two numbers without using a temporary variable.  
Input:  
Enter first number: 5  
Enter second number: 10

Expected Output:  
After swapping: first number = 10, second number = 5

Q90. Write a Java program to reverse a number using recursion.  
Input:  
Enter a number:
12345

Expected Output:  
Reversed number = 54321

Q91. Write a Java program to print the first N Fibonacci numbers using a loop.  
Input:  
Enter N: 6

Expected Output:  
Fibonacci numbers: 0 1 1 2 3 5

Q92. Write a Java program to calculate the factorial of a number using recursion.  
Input:  
Enter a number: 5

Expected Output:  
Factorial = 120

Q93. Write a Java program to check if a given number is an Armstrong number.  
Input:  
Enter a number: 153

Expected Output:  
153 is an Armstrong number.

Q94. Write a Java program to print the sum of the digits of a number.  
Input:  
Enter a number: 9876

Expected Output:  
Sum of digits = 30

Q95. Write a Java program to reverse a string using a for loop.  
Input:  
Enter a string: Java

Expected Output:  
Reversed string = avaJ

Q96. Write a Java program to find the sum of elements in an array.  
Input:  
Enter array elements: 1 2 3 4 5

Expected Output:  
Sum of elements = 15

Q97. Write a Java program to print all the numbers divisible by 5 in a given range.  
Input:  
Enter start: 1  
Enter end: 20

Expected Output:  
Numbers divisible by 5: 5 10 15

Q98. Write a Java program to find the sum of squares of odd numbers in a given range.  
Input:  
Enter start: 1  
Enter end: 10

Expected Output:  
Sum of squares of odd numbers = 165

Q99. Write a Java program to check if a number is divisible by both 3 and 5.  
Input:  
Enter a number: 15

Expected Output:  
15 is divisible by both 3 and 5.

Q100. Write a Java program to calculate the area of a triangle given its base and height.  
Input:  
Enter base: 10  
Enter height: 5

Expected Output:  
Area = 25.0