In this article, you will see how to count the number of vowels in a string using Java. A vowel is a sound such as the ones represented in writing by the letters ‘a‘, ‘e‘, ‘i‘, ‘ o‘, and ‘u‘, which you pronounce with your mouth open.
Example-1. Count Vowels in a String using Java
In this program, we check whether the one-by-one extracted single character from the string matches any of the 5 vowels (‘a‘, ‘e‘, ‘i‘, ‘ o‘, and ‘u‘) or not. If yes, then we will increment the vowels count variable. Finally, print the vowel count. let’s see the java program below:
package com.javacodepoint.string;
import java.util.Scanner;
public class CountVowels {
public static void main(String[] args) {
// Creating scanner object for reading user input
Scanner sc = new Scanner(System.in);
System.out.println("Enter a string to count Vowels: ");
String str = sc.next();
// Variable to count the vowel characters
int vowelsCount = 0;
// Iterate over the given string
for (int i = 0; i < str.length(); i++) {
// Extract a character from string
char ch = str.charAt(i);
// Check Vowel character
if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I'
|| ch == 'O' || ch == 'U') {
vowelsCount++;
}
}
// Print the count
System.out.println("The total vowels count: " + vowelsCount);
}
}
OUTPUT:
Enter a string to count Vowels:
Example
The total vowels count: 3
Example-2. Vowels Count using a String with all Vowel Characters.
In this example, we will take a string with all Vowel characters eg: String allVowels=”aeiouAEIOU”, and check whether a character from a given String is available in allVowels or not. if available then increment the count. Let’s see the java program for it below:
package com.javacodepoint.string;
import java.util.Scanner;
public class CountVowels2 {
public static void main(String[] args) {
// Creating scanner object for reading user input
Scanner sc = new Scanner(System.in);
System.out.println("Enter a string to count Vowels: ");
String str = sc.next();
// Variable to count the total Vowel characters
int vowelsCount = 0;
// All Vowels (lowercase and uppercase)
String allVowels = "aeiouAEIOU";
// Iterate over the given string
for (int i = 0; i < str.length(); i++) {
// Extract a character from string
char ch = str.charAt(i);
// Check Vowel character
if (allVowels.indexOf(ch) != -1) {
vowelsCount++;
}
}
// Print the count
System.out.println("The total vowels count: " + vowelsCount);
}
}
OUTPUT:
Enter a string to count Vowels:
Javacodepoint
The total vowels count: 6
See also:
How to count the occurrence of the given character in a string in java?
How to swap two strings without using the third variable in java?