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Java program to count number of vowels in a string

In this article of java program, we will learn how to count the number of vowels in a string?
Submitted by Jyoti Singh, on October 05, 2017

Given a string and we have to count total number of vowels in it using Java.

Example:

Input string: "includehelp"
Output:
Number of vowels: 4

In this code we have one input:

1. An int input (no. of test cases or more clearly the number of strings user wants to check (say 5 i.e user wants to check 5 strings and the program will continue for 5 inputs).
2. A string input (It will be a string entered by the user which needs to be checked).

For each string we will have two outputs

The number of vowels in string

Consider the program: It will take number of inputs, string and print total number of vowels.

import java.util.Scanner;

public class CountVowels {

	public static void main(String[] args) {
	
		Scanner Kb=new Scanner(System.in);
		System.out.println("How man strings u want to check?");
		//Take the input of no. of test cases
		int t=Kb.nextInt();
		//looping until the test cases are zero
		while(t-->0){
			//Input the string
			System.out.println("Enter the string!");
			String s=Kb.next();
			//counter to count the number of vowels in a string
			int vowels=0;
			for(int i=0;i<s.length();i++){
				//character at a particular index of string
				char ch=s.charAt(i);
				/*switch is used to check multiple condition by using different cases
				here,we will check each character that it is a vowel or not 
				*/
				switch(ch){
					case 'a':
					case 'e':
					case 'i':
					case 'o':
					case 'u':
					case 'A':
					case 'E':
					case 'I':
					case 'O':
					case 'U':
					//counter vowels will be incremented each time when a character will be a vowel
					vowels++;
					break;
					default:
					// do nothing
				}
			}
			//print the number of vowels in a string
			System.out.println(vowels);
		}
		//to give a space of one line
		System.out.println();

	}
}