100 Java Programs for Beginners with Examples and Solutions

100 Java Programs for Beginners

Learning Java becomes much easier when you practice real programs consistently. This collection contains beginner-friendly Java programs covering numbers, strings, patterns, conversions, mathematical logic, and problem-solving concepts. Each program includes explanation, examples, logic, and complete Java code.

Whether you are preparing for interviews, improving problem-solving skills, practicing Java fundamentals, or building a strong programming foundation, these Java programs will help you step by step.

Complete List of Java Programs

1. Armstrong Number in Java — Learn how to check whether a number is an Armstrong number using Java logic and examples.
2. Palindrome Number in Java — Understand palindrome logic with complete Java programs and examples.
3. Reverse a Number in Java — Learn multiple ways to reverse numbers in Java.
4. Fibonacci Series in Java — Generate Fibonacci series using loops and recursion.
5. Prime Numbers in Java — Learn prime number checking logic with optimized Java programs.
6. Perfect Number in Java — Understand perfect numbers with complete explanation and code.
7. Happy Number in Java — Learn how happy numbers work using Java programs.
8. Strong Number in Java — Check whether a number is strong using factorial logic.
9. Kaprekar Number in Java — Learn Kaprekar number logic with examples and programs.
10. Peterson Number in Java — Understand Peterson numbers and their implementation in Java.
11. Neon Number in Java — Learn how to identify neon numbers using Java.
12. Duck Number in Java — Understand duck numbers with rules and examples.
13. Tech Number in Java — Learn how to solve tech number problems in Java.
14. Disarium Number in Java — Check disarium numbers with step-by-step explanation.
15. Automorphic Number in Java — Learn automorphic number logic and implementation.
16. Spy Number in Java — Understand how spy numbers work in Java programming.
17. Abundant Number in Java — Learn how to identify abundant numbers using Java.
18. Deficient Number in Java — Understand deficient numbers with Java examples.
19. Co-Prime Numbers in Java — Learn how to find co-prime numbers using Java.
20. Twin Prime Numbers in Java — Practice twin prime logic using Java programs.
21. LCM of Two Numbers in Java — Learn LCM calculation methods in Java.
22. GCD / HCF in Java — Understand Euclidean algorithm with Java implementation.
23. Binary to Decimal Conversion in Java — Convert binary numbers into decimal using Java logic.
24. Decimal to Binary Conversion in Java — Learn decimal to binary conversion step by step.
25. Prime Factorization in Java — Understand factorization logic with Java code.
26. Perfect Square in Java — Learn how to check perfect squares in Java.
27. Perfect Square Without Math.sqrt() — Solve perfect square problems without built-in methods.
28. Square Root Without Math.sqrt() — Learn square root calculation using logic and loops.
29. Newton Raphson Square Root Program — Advanced square root calculation using Newton-Raphson method.
30. Perfect Cube in Java — Learn how to check perfect cubes in Java.
31. Perfect Cube Without Math.cbrt() — Solve cube problems without Java library methods.
32. Cube Root Without Math.cbrt() — Learn cube root calculation manually in Java.
33. Palindrome String in Java — Learn how to reverse and compare strings in Java.
34. Reverse a String in Java — Understand different ways to reverse strings.
35. Check Anagram Strings in Java — Learn anagram checking using sorting and loops.
36. String Rotation Check in Java — Understand string rotation logic using Java.
37. Compare Two Strings Without equals() — Learn string comparison logic manually.
38. Concatenate Strings Without + Operator — Learn string concatenation manually in Java.
39. Check Empty or Null String in Java — Learn how to validate strings correctly in Java.
40. Unique Characters in a String — Understand duplicate checking in strings.
41. Find Duplicate Characters in Java — Learn duplicate character detection step by step.
42. First Repeating Character in Java — Find repeating characters efficiently using Java.
43. First Non-Repeating Character in Java — Learn character frequency concepts using Java.
44. Count Character Frequency in Java — Learn frequency counting using arrays and loops.
45. Count Vowels in Java — Count vowels in strings using Java loops.
46. Count Consonants in Java — Learn consonant counting logic with examples.
47. Count Digits in a String — Learn how to count numeric digits in Java strings.
48. Count Spaces in Java String — Understand space counting logic using loops.
49. Count Words in a Sentence — Learn word counting techniques in Java.
50. String Length Without length() — Calculate string length manually using loops.
51. Count Uppercase and Lowercase Characters — Learn character classification in Java.
52. Convert String to Uppercase Without Library — Learn manual uppercase conversion logic.
53. Convert String to Lowercase Without Library — Learn lowercase conversion manually in Java.
54. Toggle Case of Characters in Java — Convert uppercase to lowercase and vice versa.
55. Capitalize First Letter of Each Word — Learn title case conversion using Java.
56. Remove Whitespaces From String — Learn whitespace removal techniques in Java.

More Java programs and problem-solving articles will continue to be added regularly. Bookmark this page and keep practicing consistently to strengthen your Java fundamentals.