Practice 70 Java Thread Programming Questions

Practice 70 Java Thread Programming Questions

Q1. Write a Java program to create a thread that prints "Hello, World!" five times.  
Expected Output:  
Hello, World!  
Hello, World!  
Hello, World!  
Hello, World!  
Hello, World!  

Q2. Write a Java program to create a thread that prints numbers from 1 to 5.  
Expected Output:  
1  
2  
3  
4  
5  

Q3. Write a Java program to create two threads where one thread prints numbers from 1 to 5, and the other thread prints "Hello" five times.  
Expected Output:  
1  
2  
3  
4  
5  
Hello  
Hello  
Hello  
Hello  
Hello  

Q4. Write a Java program to create a thread that prints a string in reverse order.  
Input:  
String = "Java"  
Expected Output:  
avaJ  

Q5. Write a Java program to demonstrate thread priority by creating two threads. The higher priority thread should print numbers from 1 to 5, and the lower priority thread should print "Java".  
Expected Output:  
1  
2  
3  
4  
5  
Java  

Q6. Write a Java program to implement a thread that counts down from 10 to 1.  
Expected Output:  
10  
9  
8  
7  
6  
5  
4  
3  
2  
1  

Q7. Write a Java program to implement a thread that prints the first 5 even numbers.  
Expected Output:  
2  
4  
6  
8  
10  

Q8. Write a Java program that demonstrates the use of the `join()` method with two threads.  
Expected Output:  
First thread completed  
Second thread completed  

Q9. Write a Java program to create a thread that prints "Java Thread" in an infinite loop.  
Expected Output:  
Java Thread (prints continuously until the program is terminated)

Q10. Write a Java program to create a thread that prints numbers from 1 to 10 with a 1-second delay between each print.  
Expected Output:  
1 (after 1 second)  
2 (after 1 second)  
3 (after 1 second)  
...  
10  

Q11. Write a Java program to demonstrate the use of the `sleep()` method with two threads.  
Expected Output:  
Thread 1  
Thread 2 (after 1-second delay)  

Q12. Write a Java program to implement a thread that prints the multiplication table of 2.  
Expected Output:  
2 x 1 = 2  
2 x 2 = 4  
2 x 3 = 6  
...  

Q13. Write a Java program to create a thread that prints numbers from 1 to 100 in intervals of 10.  
Expected Output:  
1  
11  
21  
...  
91  

Q14. Write a Java program to implement two threads where one prints "A" and the other prints "B" alternately.  
Expected Output:  
A  
B  
A  
B  
...  

Q15. Write a Java program to create a thread that prints "Thread Running" every 2 seconds.  
Expected Output:  
Thread Running (prints every 2 seconds)  

Q16. Write a Java program to create a thread that prints a countdown from 5 to 1 with a 2-second delay.  
Expected Output:  
5  
4  
3  
2  
1  

Q17. Write a Java program to demonstrate thread synchronization by using two threads that access the same resource.  
Expected Output:  
Thread 1 accessing the resource  
Thread 2 accessing the resource  

Q18. Write a Java program to implement a thread that prints numbers from 1 to 5 and then stops.  
Expected Output:  
1  
2  
3  
4  
5  

Q19. Write a Java program to create a thread that prints "Thread Completed" after a 3-second delay.  
Expected Output:  
Thread Completed (after 3 seconds)  

Q20. Write a Java program to create a thread that simulates a task running for 5 seconds, then prints "Task Completed".  
Expected Output:  
Task Completed (after 5 seconds)  

Q21. Write a Java program to implement two threads that print numbers from 1 to 10, and the other prints alphabets from A to J.  
Expected Output:  
1  
A  
2  
B  
3  
C  
...  

Q22. Write a Java program to create a thread that prints "Task Started", waits for 5 seconds, and then prints "Task Ended".  
Expected Output:  
Task Started  
(Task waits for 5 seconds)  
Task Ended  

Q23. Write a Java program to demonstrate thread creation using the `Runnable` interface.  
Expected Output:  
Thread is running  

Q24. Write a Java program to create a thread that prints the Fibonacci series up to the 10th term.  
Expected Output:  
0  
1  
1  
2  
3  
5  
8  
13  
21  
34  

Q25. Write a Java program to create a thread that checks if a number is prime.  
Input:  
Number = 7  
Expected Output:  
7 is prime  

Q26. Write a Java program to implement a thread that prints the square of numbers from 1 to 5.  
Expected Output:  
1  
4  
9  
16  
25  

Q27. Write a Java program to create a thread that prints numbers from 10 to 1 in reverse order.  
Expected Output:  
10  
9  
8  
...  
1  

Q28. Write a Java program to create a thread that simulates a delay of 3 seconds and then prints "Operation Complete".  
Expected Output:  
Operation Complete (after 3 seconds)  

Q29. Write a Java program to create a thread that counts from 1 to 5 with a delay of 500 milliseconds between each print.  
Expected Output:  
1 (after 500 ms)  
2 (after 500 ms)  
...  

Q30. Write a Java program to implement a thread that prints the prime numbers between 1 and 50.  
Expected Output:  
2  
3  
5  
7  
...  

Q31. Write a Java program to create a thread that prints the factorial of a number.  
Input:  
Number = 5  
Expected Output:  
Factorial of 5 = 120  

Q32. Write a Java program to create a thread that prints the sum of numbers from 1 to 5.  
Expected Output:  
Sum = 15  

Q33. Write a Java program to create a thread that prints the product of numbers from 1 to 5.  
Expected Output:  
Product = 120  

Q34. Write a Java program to demonstrate thread communication using `wait()` and `notify()`.  
Expected Output:  
Thread 1 waiting  
Thread 2 notified  

Q35. Write a Java program to create a thread that prints the current system time every second.  
Expected Output:  
System Time: [current time] (prints every second)  

Q36. Write a Java program to create a thread that prints "Good Morning" 5 times with a 1-second delay.  
Expected Output:  
Good Morning  
Good Morning  
...  

Q37. Write a Java program to implement a thread that counts the number of occurrences of a character in a string.  
Input:  
String = "Java programming", Character = 'a'  
Expected Output:  
Occurrences of 'a' = 2  

Q38. Write a Java program to create a thread that calculates the square root of a number.  
Input:  
Number = 16  
Expected Output:  
Square root of 16 = 4.0  

Q39. Write a Java program to demonstrate thread synchronization using `synchronized` block.  
Expected Output:  
Thread 1 accessing synchronized block  
Thread 2 accessing synchronized block  

Q40. Write a Java program to create a thread that prints "Thread Active" five times with a 2-second delay.  
Expected Output:  
Thread Active  
Thread Active  
...  

Q41. Write a Java program to implement a thread that prints the first 5 multiples of 5.  
Expected Output:  
5  
10  
15  
20  
25  

Q42. Write a Java program to create a thread that reverses an array of integers.  
Input:  
Array = [1, 2, 3, 4, 5]  
Expected Output:  
[5, 4, 3, 2, 1]  

Q43. Write a Java program to create a thread that finds the largest number in an array.  
Input:  
Array = [1, 5, 3, 9, 2]  
Expected Output:  
Largest number = 9  

Q44. Write a Java program to create a thread that calculates the sum of digits of a number.  
Input:  
Number = 123  
Expected Output:  
Sum of digits = 6  

Q45. Write a Java program to create a thread that calculates the factorial of a number recursively.  
Input:  
Number = 4  
Expected Output:  
Factorial of 4 = 24  

Q46. Write a Java program to create a thread that simulates a task taking 2 seconds to complete.  
Expected Output:  
Task Completed (after 2 seconds)  

Q47. Write a Java program to create a thread that calculates the sum of all even numbers from 1 to 10.  
Expected Output:  
Sum of even numbers = 30  

Q48. Write a Java program to create a thread that counts down from a given number to 1.  
Input:  
Number = 6  
Expected Output:  
6  
5  
4  
3  
2  
1  

Q49. Write a Java program to implement a thread that finds the square of a number.  
Input:  
Number = 5  
Expected Output:  
Square of 5 = 25  

Q50. Write a Java program to create a thread that prints "Thread Running" 5 times.  
Expected Output:  
Thread Running  
Thread Running  
...  

Q51. Write a Java program to create a thread that prints numbers from 1 to 10 with a delay of 1 second.  
Expected Output:  
1  
2  
...  

Q52. Write a Java program to implement a thread that checks whether a given number is even or odd.  
Input:  
Number = 5  
Expected Output:  
5 is odd  

Q53. Write a Java program to create a thread that finds the GCD of two numbers.  
Input:  
Numbers = 24, 36  
Expected Output:  
GCD = 12  

Q54. Write a Java program to implement a thread that checks if a given string is a palindrome.  
Input:  
String = "madam"  
Expected Output:  
madam is a palindrome  

Q55. Write a Java program to create a thread that prints a multiplication table for any number.  
Input:  
Number = 7  
Expected Output:  
7 x 1 = 7  
7 x 2 = 14  
...  

Q56. Write a Java program to create a thread that finds the sum of the first 100 natural numbers.  
Expected Output:  
Sum = 5050  

Q57. Write a Java program to create a thread that prints the Fibonacci sequence up to a given number.  
Input:  
Number = 10  
Expected Output:  
0 1 1 2 3 5 8  

Q58. Write a Java program to create a thread that checks if a number is a perfect number.  
Input:  
Number = 6  
Expected Output:  
6 is a perfect number  

Q59. Write a Java program to create a thread that prints numbers in an arithmetic progression.  
Input:  
Start = 2, Difference = 3, Count = 5  
Expected Output:  
2 5 8 11 14  

Q60. Write a Java program to create a thread that prints the sum of squares of numbers from 1 to 5.  
Expected Output:  
55  

Q61. Write a Java program to create a thread that prints numbers from 1 to 10 in increasing order.  
Expected Output:  
1  
2  
...  

Q62. Write a Java program to create a thread that calculates the power of a number.  
Input:  
Base = 2, Exponent = 3  
Expected Output:  
2^3 = 8  

Q63. Write a Java program to create a thread that prints the prime numbers up to 100.  
Expected Output:  
2 3 5 7 11 13 ...  

Q64. Write a Java program to create a thread that computes the sum of an array of integers.  
Input:  
Array = [1, 2, 3, 4, 5]  
Expected Output:  
Sum = 15  

Q65. Write a Java program to create a thread that calculates the product of all numbers in an array.  
Input:  
Array = [1, 2, 3, 4]  
Expected Output:  
Product = 24  

Q66. Write a Java program to create a thread that simulates a clock (printing time every second).  
Expected Output:  
Time: [current time] (prints every second)  

Q67. Write a Java program to create a thread that prints the first N prime numbers.  
Input:  
N = 5  
Expected Output:  
2 3 5 7 11  

Q68. Write a Java program to create a thread that calculates the sum of the digits of a given number.  
Input:  
Number = 123  
Expected Output:  
Sum of digits = 6  

Q69. Write a Java program to create a thread that simulates a countdown timer from a given number.  
Input:  
Number = 10  
Expected Output:  
10  
9  
...  

Q70. Write a Java program to create a thread that prints numbers divisible by both 3 and 5 in a given range.  
Input:  
Range = 1 to 30  
Expected Output:  
15  
30  

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