🧩 Java String Problems for Beginners

Strings are one of the most frequently used data types in Java. Whether you’re validating user input, formatting text, or analyzing data, mastering string operations is essential. In this post, we’ll explore a set of beginner-friendly Java string problems that help you practice key concepts like concatenation, character counting, string reversal, and palindrome checking. Each problem focuses on improving your problem-solving skills using loops, conditions, and Java’s built-in string methods.

Let’s get started and make your Java string fundamentals stronger with hands-on practice.

🧠 Problem Set — Java String Challenges

🧩 Problem 1: Reverse a String

Description:

Write a Java program to reverse a given string without using the built-in reverse() method.

Hint:

Use a loop that iterates through the string from end to start and builds a new reversed string.

Sample Code:

public class ReverseString {

public static void main(String[] args) {

String input = "Hello";

String reversed = "";

for (int i = input.length() - 1; i >= 0; i--) {

reversed += input.charAt(i);

}

System.out.println("Reversed: " + reversed);

}

}

🧩 Problem 2: Check if a String is a Palindrome

Description:

A string is called a palindrome if it reads the same forward and backward. Write a Java program to check if the input string is a palindrome.

Example Input:

madam

Example Output:

Palindrome

Hint:

Compare the original string with its reversed version.

Sample Code:

public class PalindromeCheck {

public static void main(String[] args) {

String word = "madam";

String reversed = new StringBuilder(word).reverse().toString();

if (word.equalsIgnoreCase(reversed)) {

System.out.println("Palindrome");

} else {

System.out.println("Not a Palindrome");

}

}

}

🧩 Problem 3: Count the Number of Vowels in a String

Description:

Write a program that counts the number of vowels (a, e, i, o, u) in a string.

Example Input:

Java Programming

Example Output:

Vowel Count: 5

Hint:

Use a loop to check each character and count if it matches a vowel.

Sample Code:

public class CountVowels {

public static void main(String[] args) {

String str = "Java Programming";

int count = 0;

str = str.toLowerCase();

for (int i = 0; i < str.length(); i++) {

char ch = str.charAt(i);

if ("aeiou".indexOf(ch) != -1) {

count++;

}

}

System.out.println("Vowel Count: " + count);

}

}

🧩 Problem 4: Count Words in a String

Description:

Write a Java program to count how many words are present in a given string.

Example Input:

Java is fun to learn

Example Output:

Word Count: 5

Hint:

Use the split() method to divide the string by spaces and count the words.

Sample Code:

public class WordCount {

public static void main(String[] args) {

String sentence = "Java is fun to learn";

String[] words = sentence.trim().split("\\s+");

System.out.println("Word Count: " + words.length);

}

}

🧩 Problem 5: Remove All Whitespace from a String

Description:

Write a Java program that removes all spaces, tabs, and newline characters from a given string.

Example Input:

Java String Practice

Example Output:

JavaStringPractice

Hint:

Use replaceAll() with a regex pattern.

Sample Code:

public class RemoveSpaces {

public static void main(String[] args) {

String text = "Java String Practice";

text = text.replaceAll("\\s+", "");

System.out.println("Without Spaces: " + text);

}

💡 Key Takeaways

These simple yet powerful Java string problems help you build a strong base in text manipulation. Through this exercise, you’ve learned how to:

Use loops to access characters in a string

Apply conditional logic to check for vowels and palindromes

Use built-in methods like split(), replaceAll(), and StringBuilder.reverse()

Understand how Java treats strings as immutable objects

Practicing these will boost your confidence and prepare you for intermediate-level problems like substring extraction, anagram checking, and frequency counting.

#JavaStringProblems #JavaProgramming #CodingPractice #LearnJava #BeginnersGuide