Let's create a Java method that takes a string as input and returns the number of vowels present in it along with a detailed explanation:



public class VowelCounter { 
public static void main(String[] args) {
String inputString = "Hello, World!";
int vowelCount = countVowels(inputString); 
 System.out.println("Number of vowels in the string: " + vowelCount); 
 }
public static int countVowels(String input) {
// Convert the input string to lowercase to handle both upper and lowercase vowels
        input = input.toLowerCase();
// Initialize a variable to keep track of the vowel count 
int count = 0; 
// Define a string containing all vowels 
String vowels = "aeiou"; 
// Loop through each character in the input string 
for (int i = 0; i < input.length(); i++) {
char ch = input.charAt(i);
// Check if the character is a vowel (contained in the vowels string)

            if (vowels.indexOf(ch) != -1) {
 count++; 
 } 
 } 
return count;
    } 
}

Explanation:

1. We start with the main method, where we declare and initialize the inputString variable with the string for which we want to count the vowels. In this example, the inputString is set to "Hello, World!".

2. Next, we call the countVowels method, passing the inputString as an argument, to obtain the count of vowels in the string.

3. In the countVowels method, we begin by converting the input string to lowercase using the toLowerCase() method. This step is essential to handle both uppercase and lowercase vowels uniformly.

4. We then initialize a variable called count to keep track of the number of vowels in the string. We set it to 0 initially.

5. To identify vowels in the string, we define string vowels containing all lowercase vowels: "aeiou".

6. Next, we use a for loop to iterate through each character in the input string. We use the charAt() method to retrieve each character at the given index i.

7. Inside the loop, we check if the current character (ch) is a vowel by using the indexOf() method on the vowel string. If the index is not equal to -1, it means the character is a vowel, and we increment the count.

8. The loop continues until we check all characters in the input string.

9. Finally, we return the count, which represents the number of vowels present in the input string.

10. In the main method, we print the result, displaying the number of vowels in the input string.


By implementing this method, we can efficiently count the number of vowels in any given string. The method handles both uppercase and lowercase characters and provides an accurate vowel count.