Given a string, count the total number of vowels (a, e, i, o, u) in it. There are two methods to count total number of vowels in a string.
- Iterative
- Recursive
Examples:
Input : abc de Output : 2 Input : neveropen portal Output : 7
1. Iterative Method:
Below is the implementation:
C++
// C++ program to count vowels in a string #include<iostream> using namespace std; // Function to check the Vowel bool isVowel(char ch) { ch = toupper(ch); return (ch=='A' || ch=='E' || ch=='I' || ch=='O' || ch=='U'); } // Returns count of vowels in str int countVowels(string str) { int count = 0; for (int i=0; i<str.length(); i++) if (isVowel(str[i])) // Check for vowel ++count; return count; } // Main Calling Function int main() { //string object string str = "abc de"; // Total numbers of Vowel cout << countVowels(str) << endl; return 0; } |
Java
// Java program to count vowels in a string public class GFG { // Function to check the Vowel static boolean isVowel(char ch) { ch = Character.toUpperCase(ch); return (ch=='A' || ch=='E' || ch=='I' || ch=='O' || ch=='U'); } // Returns count of vowels in str static int countVowels(String str) { int count = 0; for (int i = 0; i < str.length(); i++) if (isVowel(str.charAt(i))) // Check for vowel ++count; return count; } // Driver code public static void main(String args[]) { //string object String str = "abc de"; // Total numbers of Vowel System.out.println(countVowels(str)); } } // This code is contributed by Sumit Ghosh |
Python3
# Python3 program to count vowels # in a string # Function to check the Vowel def isVowel(ch): return ch.upper() in ['A', 'E', 'I', 'O', 'U'] # Returns count of vowels in str def countVowels(str): count = 0 for i in range(len(str)): # Check for vowel if isVowel(str[i]): count += 1 return count # Driver Code # string object str = 'abc de' # Total number of Vowels print(countVowels(str)) # This code is contributed # by SamyuktaSHegde |
C#
// C# program to count vowels in a string using System; class GFG { // Function to check the Vowel public static bool isVowel(char ch) { ch = char.ToUpper(ch); return (ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U'); } // Returns count of vowels in str public static int countVowels(string str) { int count = 0; for (int i = 0; i < str.Length; i++) { // Check for vowel if (isVowel(str[i])) { ++count; } } return count; } // Driver code public static void Main(string[] args) { //string object string str = "abc de"; // Total numbers of Vowel Console.WriteLine(countVowels(str)); } } // This code is contributed by Shrikant13 |
PHP
<?php // PHP program to count vowels in a string // Function to check the Vowel function isVowel($ch) { $ch = strtoupper($ch); return ($ch =='A' || $ch =='E' || $ch =='I' || $ch =='O' || $ch =='U'); } // Returns count of vowels in str function countVowels($str) { $count = 0; for ($i = 0; $i < strlen($str); $i++) if (isVowel($str[$i])) // Check for vowel ++$count; return $count; } // Driver Code //string object $str = "abc de"; // Total numbers of Vowel echo countVowels($str) . "\n"; // This code is contributed // by Akanksha Rai ?> |
Javascript
<script> // JavaScript program to count vowels in a string // Function to check the Vowel function isVowel(ch) { ch = ch.toUpperCase(); return ch == "A" || ch == "E" || ch == "I" || ch == "O" || ch == "U"; } // Returns count of vowels in str function countVowels(str) { var count = 0; for (var i = 0; i < str.length; i++) if (isVowel(str[i])) // Check for vowel ++count; return count; } // Main Calling Function // string object var str = "abc de"; // Total numbers of Vowel document.write(countVowels(str)); document.write("<br>"); // This code is contributed by rdtank. </script> |
Output
2
Time Complexity: O(n), where n is the length of the string
Auxiliary Space: O(1)
2. Recursive Method:
Below is the implementation:
C++
// Recursive C++ program to count the total // number of vowels using recursion #include<iostream> using namespace std; // Function to check the Vowel bool isVowel(char ch) { ch = toupper(ch); return (ch=='A' || ch=='E' || ch=='I' || ch=='O' || ch=='U'); } // to count total number of vowel from 0 to n int countVovels(string str, int n) { if (n == 1) return isVowel(str[n-1]); return countVovels(str, n-1) + isVowel(str[n-1]); } // Main Calling Function int main() { // string object string str = "abc de"; // Total numbers of Vowel cout << countVovels(str, str.length()) << endl; return 0; } |
Java
// Recursive Java program to count the total // number of vowels using recursion public class GFG { // Function to check the Vowel 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 = "abc de"; // Total numbers of Vowel System.out.println(countVowels(str,str.length())); } } // This code is contributed by Sumit Ghosh |
Python 3
# Recursive Python 3 program to count the # total number of vowels using recursion # Function to check the Vowel def isVowel(ch): return ch.upper() in ['A', 'E', 'I', 'O', 'U'] # to count total number of # vowel from 0 to n def countVovels(str, n): if (n == 1): return isVowel(str[n - 1]); return (countVovels(str, n - 1) + isVowel(str[n - 1])); # Driver Code # string object str = "abc de"; # Total numbers of Vowel print(countVovels(str, len(str))) # This code is contributed # by Akanksha Rai |
C#
using System; // Recursive C# program to count the total // number of vowels using recursion public class GFG { // Function to check the Vowel public static int isVowel(char ch) { ch = char.ToUpper(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 public static int countVowels(string str, int n) { if (n == 1) { return isVowel(str[n - 1]); } return countVowels(str, n - 1) + isVowel(str[n - 1]); } // Main Calling Function public static void Main(string[] args) { //string object string str = "abc de"; // Total numbers of Vowel Console.WriteLine(countVowels(str,str.Length)); } } // This code is contributed by Shrikant13 |
PHP
<?php // Recursive PHP program to count the total // number of vowels using recursion // Function to check the Vowel function isVowel($ch) { $ch = strtoupper($ch); return ($ch == 'A' || $ch == 'E' || $ch == 'I' || $ch == 'O' || $ch == 'U'); } // to count total number of // vowel from 0 to n function countVovels($str, $n) { if ($n == 1) return isVowel($str[$n - 1]); return countVovels($str, $n - 1) + isVowel($str[$n - 1]); } // Driver Code // string object $str = "abc de"; // Total numbers of Vowel echo countVovels($str, strlen($str)) . "\n"; // This code is contributed // by Akanksha Rai ?> |
Javascript
<script> // Recursive JavaScript program to count the total // number of vowels using recursion // Function to check the Vowel function isVowel(ch) { ch = ch.toUpperCase(); return (ch=='A' || ch=='E' || ch=='I' || ch=='O' || ch=='U'); } // to count total number of vowel from 0 to n function countVovels(str,n) { if (n == 1) return isVowel(str[n-1]); return countVovels(str, n-1) + isVowel(str[n-1]); } // Main Calling Function // string object let str = "abc de"; // Total numbers of Vowel document.write(countVovels(str, str.length)); // This code is contributed by shinjanpatra </script> |
Output
2
Time Complexity: O(n), where n is the length of the string
Auxiliary Space: O(n), where n is the length of the string since the function is calling itself n times.
How Recursive Code Working.
This article is contributed by Prakhar Agrawal. If you like neveropen and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to review-team@geeksforgeeks.org. See your article appearing on the neveropen main page and help other Geeks.
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