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 : geeksforgeeks 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.