Java Program to Count Vowels and Consonants in a String

To count vowels and consonants in a String, iterate over each character of the string and check if the character is vowel or consonant. If the character is vowel, increment vowel count, or if the character is consonant, increment consonant count.

In this tutorial, we shall write Java program to count number of vowels and consonants in a string.

Count Vowels and Consonants in String using For Loop

Algorithm

We shall use the following algorithm to write Java program for counting vowels and consonants in the string.

  1. Start.
  2. Read input string to a variable str, or initialize the variable with a string constant.
  3. Transform input string to lower case and replace any character other than alphabet with an empty string. Store the resulting string in alpha.
  4. Initialize vowels with 0 and consonants with 0. These are the counters for vowels and consonants respectively in the string.
  5. For each character in alpha, check if the character is vowel. If true, increment vowels, else increment consonants.
  6. vowels has the count for number of vowels in the string, and consonants have the count for number of consonants in the string.
  7. Stop.

Java Program

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/**
 * Java Program - Count Vowels and Consonants
 */

public class CountVowelConsonant {

	public static void main(String[] args) {

		String str = "apple is fruit.";
		
		String alpha = str.toLowerCase().replaceAll("[^a-z]", "");
		
		int vowels = 0;
		int consonants = 0;
		
		for (char ch: alpha.toCharArray()) {
			if(ch == 'a' || ch=='e' || ch == 'i' || ch=='o' || ch == 'u')
				vowels++;
			else
				consonants++;
		}
		
		System.out.println("Vowels : "+vowels);
		System.out.println("Consonants : "+consonants);
	}
}

Output

Vowels : 5
Consonants : 7

Conclusion

In this Java Tutorial, we learned how to count vowels and consonants in a given string.