Java Program to Count Vowels and Consonants in a String

Write a Java Program to Count Vowels and Consonants in a String with an example. In this Java count consonants and vowels in a string example, we first used for loop to iterate vowConsStr. Inside the loop, we assigned (ch = vowConsStr.charAt(i)) each character to ch to keep the code simple. Next, we used the Else If statement. 

Within the if condition, we check whether the character is equal o a, e, i o, u, A, E, I, O, and U. If true, we increment the value of the vowel. In the else if statement, we used (ch >= ‘a’ && ch <= ‘z’ || ch >= ‘A’ && ch <= ‘Z’) to check whether the character is an alphabet. If True, we increment the consonant value. Here, we can also use else if (Character.isAlphabetic(ch)).

import java.util.Scanner;

public class CountVowCons1 {
	private static Scanner sc;
	public static void main(String[] args) {
		String vowConsStr;
		int i, vowels, consonants;
		vowels = consonants = 0;
		char ch;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Vowel, Consonant String =  ");
		vowConsStr = sc.nextLine();
		
		for(i = 0; i < vowConsStr.length(); i++)
		{
			ch = vowConsStr.charAt(i);
			if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' ||
					ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U') {
				vowels++;
			}
			else if (ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z'){
				consonants++;
			}
		}		
		System.out.println("\nNumber of Vowel Characters     =  " + vowels);
		System.out.println("Number of Consonant Characters =  " + consonants);
	}
}

Java Program to Count Vowels and Consonants in a String using While Loop

The following toLowerCase() statement converts the given string to lowercase. 

String lw_vowConsStr = vowConsStr.toLowerCase();

Instead of checking both uppercase and lowercase letters, we compare only lowercase and counting the vowels and consonants.

import java.util.Scanner;

public class CountVowCons2 {
	private static Scanner sc;
	public static void main(String[] args) {
		String vowConsStr;
		int i, vowels, consonants;
		i = vowels = consonants = 0;
		char ch;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Vowel, Consonant String =  ");
		vowConsStr = sc.nextLine();
		
		String lw_vowConsStr = vowConsStr.toLowerCase();
		
		while(i < lw_vowConsStr.length())
		{
			ch = lw_vowConsStr.charAt(i);
			if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
				vowels++;
			}
			else if(ch >= 'a' && ch <= 'z') {
				consonants++;
			}
			i++;
		}		
		System.out.println("\nNumber of Vowel Characters     =  " + vowels);
		System.out.println("Number of Consonant Characters =  " + consonants);
	}
}

In this Java Count Consonants and Vowels in a String example, we compare the ASCII values instead of comparing characters.

import java.util.Scanner;

public class CountVowCons3 {
	private static Scanner sc;
	public static void main(String[] args) {
		String vowConsStr;
		int i, vowels, consonants;
		vowels = consonants = 0;
		int cp;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Vowel, Consonant String =  ");
		vowConsStr = sc.nextLine();
		
		String up_vowConsStr = vowConsStr.toUpperCase();
		
		for(i = 0; i < up_vowConsStr.length(); i++)
		{
			cp = up_vowConsStr.codePointAt(i);
			if(cp == 65 || cp == 69 || cp == 73 || cp == 79 || cp == 85) {
				vowels++;
			}
			else if(cp >= 65 && cp <= 90 || cp >= 97 && cp <= 122)  {
				consonants++;
			}
		}		
		System.out.println("\nNumber of Vowel Characters     =  " + vowels);
		System.out.println("Number of Consonant Characters =  " + consonants);
	}
}

This Java code to Count String Vowels and Consonants is the same as the above. Here, we separated the Vowels and Consonants logic using Java functions.

import java.util.Scanner;

public class CountVowCons4 {
	private static Scanner sc;
	public static void main(String[] args) {
		String vowConsStr;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Vowel, Consonant String =  ");
		vowConsStr = sc.nextLine();
		
		VowOrCons(vowConsStr.toLowerCase());
	}
	public static void VowOrCons (String vowConsStr) {
		int i, vowels, consonants;
		vowels = consonants = 0;
		char ch;
		
		for(i = 0; i < vowConsStr.length(); i++)
		{
			ch = vowConsStr.charAt(i);
			if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
				vowels++;
			}
			else if(ch >= 'a' && ch <= 'z') {
				consonants++;
			}
		}		
		System.out.println("\nNumber of Vowel Characters     =  " + vowels);
		System.out.println("Number of Consonant Characters =  " + consonants);

	}
}