Java program to count the number of vowels in a String

March 7, 2024

Program to Count the Number of vowels

Program to Count the Number of vowels we’re going to check how many vowels are present in a given String . There are five vowels in English vocabulary, they are – ‘a’, ‘e’, ‘i’, ‘o’, ‘u’.

A String is entered in this case is “s” variable So, we need to check how many vowels are present in given string

For Example, in the string prepinsta then in that case then vowesl are 3 (a,e,i)

Program count the number of vowels in a string

Algorithm

  • Take a String input from user store in variable called “s” 
  • Convert String to char array using toCharArray() 
  • Start for loop from i=0 to i<s.length()
  • Check condition if s.charAt(i)==’a’ or s.charAt(i)==’e’ or s.charAt(i)==’i’ or s.charAt(i)==’o’ or s.charAt(i)==’o’ to increment vowel++
  • Take else if part s.charAt(i)>=’a’ && s.charAt(i)<=’z’ to increment consonant ++
  • Take another else if part s.charAt(i)>=’1′ && s.charAt(i)<=’9′ to increment digit++
  • Take another else if part s.charAt(i)==’ ‘ to increment whitespaces++
  • Take else part to increment symbols++

Code in Java

Run 
// Write a program to calculate the number of vowels present in the string in java
import java.util.Scanner;

public class  Main{

	public static void main(String[] args) {
		String s = "prepinsta";
		char[] c = s.toCharArray();
		int vowel=0;
		
		for (int i = 0; i < s.length(); i++) { 
            if(s.charAt(i)=='a' || s.charAt(i)=='e' || s.charAt(i)=='i' || s.charAt(i)=='o' || s.charAt(i)=='u') 
                vowel++; 
		}
  
	System.out.println("Vowels: " + vowel);
    }
}

Output 

Vowels: 3

Method 2

  • First take the string input in a string variable and make a function countVowels(str,str.length())
  • if the value of n that is (length of string) is 1 then we will return . (This is the base case)
  • if the size of the string is not 1 then countVowels(str, n-1) + isVowel(str[n-1])
  • Here isVowel(str[n-1]) will be called if the character is vowel then this will return 1 otherwise 0
Run 
public class Main {
    static int isVowel(char ch) {
        ch = Character.toUpperCase(ch);
        if (ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U')
            return 1;
        else
            return 0;
    }
    // to count total number of vowel from 0 to n
    static int countVowels(String str, int n) {
        if (n == 1) return isVowel(str.charAt(n - 1));
        return countVowels(str, n - 1) + isVowel(str.charAt(n - 1));
    }
    // Main Calling Function
    public
    static void main(String args[]) {
        // string object
        String str = "prepinsta";

    // Total numbers of Vowel
    System.out.print("Total number of Vowel = ");
    System.out.println(countVowels(str, str.length()));
  }
}

Output

Total number of Vowel = 3
 
 

Remove brackets from an algebraic expression

Remove spaces from a string

Remove the vowels from a String

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14 comments on “Java program to count the number of vowels in a String”


  • lalit

    public class Noofvowels {

    public static void main(String arg[]) {
    String s = “Lalit”;
    int count = 0;
    for(int i=0;i<s.length();i++) {
    char c= s.charAt(i);

    c=Character.toUpperCase(c);
    if(c=='A'||c=='E'||c=='I'||c=='O'||c=='U') {
    count++;
    }
    }
    System.out.println(count);
    }
    }

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