Count consonants in a string (Iterative and recursive methods)

Last Updated : 20 Feb, 2023

Given a string, count total number of consonants in it. A consonant is an English alphabet character that is not vowel (a, e, i, o and u). Examples of constants are b, c, d, f, and g.

Examples :

Input : abc de
Output : 3
There are three consonants b, c and d.

Input : geeksforgeeks portal
Output : 12

1. Iterative Method

C++

// Iterative CPP program to count total number 
// of consonants  
#include <iostream> 
using namespace std; 
  
// Function to check for consonant 
bool isConsonant(char ch) 
{ 
    // To handle lower case 
    ch = toupper(ch); 
  
    return !(ch == 'A' || ch == 'E' ||  
            ch == 'I' || ch == 'O' ||  
            ch == 'U') && ch >= 65 && ch <= 90; 
} 
  
int totalConsonants(string str) 
{ 
    int count = 0; 
    for (int i = 0; i < str.length(); i++)  
  
        // To check is character is Consonant 
        if (isConsonant(str[i])) 
            ++count; 
    return count; 
} 
  
// Driver code 
int main() 
{ 
    string str = "abc de"; 
    cout << totalConsonants(str); 
    return 0; 
} 

Java

// Iterative Java program 
// to count total number 
// of consonants  
  
import java.io.*; 
  
class GFG { 
  
    // Function to check for consonant 
    static boolean isConsonant(char ch) 
    { 
        // To handle lower case 
        ch = Character.toUpperCase(ch); 
       
        return !(ch == 'A' || ch == 'E' ||  
                ch == 'I' || ch == 'O' ||  
                ch == 'U') && ch >= 65 && ch <= 90; 
    } 
   
    static int totalConsonants(String str) 
    { 
        int count = 0; 
        for (int i = 0; i < str.length(); i++)  
       
            // To check is character is Consonant 
            if (isConsonant(str.charAt(i))) 
                ++count; 
        return count; 
    } 
      
    // Driver code 
    public static void main(String args[]) 
    { 
        String str = "abc de"; 
        System.out.println( totalConsonants(str)); 
    } 
} 
  
// This code is contributed by Nikita Tiwari. 

Python3

# Iterative Python3 program to count  
# total number of consonants  
  
# Function to check for consonant 
def isConsonant(ch): 
      
    # To handle lower case 
    ch = ch.upper() 
  
    return not (ch == 'A' or ch == 'E' or 
                ch == 'I' or ch == 'O' or 
                ch == 'U') and ord(ch) >= 65 and ord(ch) <= 90
  
def totalConsonants(string): 
      
    count = 0
      
    for i in range(len(string)): 
  
        # To check is character is Consonant 
        if (isConsonant(string[i])): 
            count += 1
              
    return count 
  
# Driver code 
string = "abc de"
print(totalConsonants(string)) 
  
  
# This code id contributed by Ansu Kumari. 

C#

// Iterative C# program to count  
// total number of consonants  
using System; 
  
class GFG { 
  
    // Function to check for consonant 
    static bool isConsonant(char ch) 
    { 
        // To handle lower case 
        ch = Char.ToUpper(ch); 
      
        return !(ch == 'A' || ch == 'E' ||  
                 ch == 'I' || ch == 'O' ||  
                 ch == 'U') && ch >= 65 && ch <= 90; 
    } 
  
    static int totalConsonants(String str) 
    { 
        int count = 0; 
        for (int i = 0; i < str.Length; i++)  
      
            // To check is character is Consonant 
            if (isConsonant(str[i])) 
                ++count; 
        return count; 
    } 
      
    // Driver code 
    public static void Main() 
    { 
        String str = "abc de"; 
        Console.Write( totalConsonants(str)); 
    } 
} 
  
// This code is contributed by nitin mittal. 

PHP

<?php  
// Iterative PHP program to count total number 
// of consonants  
   
// Function to check for consonant 
function isConsonant($ch) 
{ 
    // To handle lower case 
    $ch = strtoupper($ch); 
   
    return !($ch == 'A' || $ch == 'E' ||  
            $ch == 'I' || $ch == 'O' ||  
            $ch == 'U') && ord($ch) >= 65 && ord($ch) <= 90; 
} 
   
function totalConsonants($str) 
{ 
    $count = 0; 
    for ($i = 0; $i < strlen($str); $i++)  
   
        // To check is character is Consonant 
        if (isConsonant($str[$i])) 
            ++$count; 
    return $count; 
} 
   
// Driver code 
  
$str = "abc de"; 
echo totalConsonants($str); 
return 0; 
 // This code is contributed by Ita_c. 
?> 

Javascript

<script> 
      // Iterative JavaScript program to count total number 
      // of consonants 
  
      // Function to check for consonant 
      function isConsonant(ch) 
      { 
        // To handle lower case 
        ch = ch.toUpperCase(); 
  
        console.log(ch); 
  
        return ( 
          !(ch == "A" || ch == "E" || ch == "I" || ch == "O" || ch == "U") && 
          ch.match(/[A-Z]/i) 
        ); 
      } 
  
      function totalConsonants(str) { 
        var count = 0; 
        for (var i = 0; i < str.length; i++) 
          // To check is character is Consonant 
          if (isConsonant(str[i])) ++count; 
        return count; 
      } 
  
      // Driver code 
      var str = "abc de"; 
      document.write(totalConsonants(str)); 
        
      // This code is contributed by rdtank. 
    </script>

Output

Time Complexity: O(n), where n is the length of the string
Auxiliary Space: O(1)

2. Recursive Method

C++

// Recursive CPP program to count total number 
// of consonants  
#include <iostream> 
using namespace std; 
  
// Function to check for consonant 
bool isConsonant(char ch) 
{ 
    // To handle lower case 
    ch = toupper(ch); 
  
    return !(ch == 'A' || ch == 'E' ||  
            ch == 'I' || ch == 'O' ||  
            ch == 'U') && ch >= 65 && ch <= 90; 
} 
  
// to count total number of consonants from  
// 0 to n-1 
int totalConsonants(string str, int n) 
{ 
    if (n == 1) 
        return isConsonant(str[0]); 
  
    return totalConsonants(str, n - 1) +  
           isConsonant(str[n-1]); 
} 
  
// Driver code 
int main() 
{ 
    string str = "abc de"; 
    cout << totalConsonants(str, str.length()); 
    return 0; 
} 

Java

// Recursive Java program to count  
// total number of consonants  
import java.util.*; 
import java.lang.*; 
  
class GFG 
{ 
  
// Function to check for consonant 
static boolean isConsonant(char ch) 
{ 
    // To handle lower case 
    ch = Character.toUpperCase(ch); 
  
    return (ch == 'A' || ch == 'E' ||  
            ch == 'I' || ch == 'O' ||  
            ch == 'U')== false && ch >= 65 && ch <= 90; 
} 
  
// to count total number  
// of consonants from  0 to n-1 
static int totalConsonants(String str, int n) 
{ 
    if (n == 1) 
    { 
        if(isConsonant(str.charAt(0))) 
            return 1; 
        else
            return 0; 
    } 
      
    if(isConsonant(str.charAt(n - 1))) 
        return totalConsonants(str, n - 1) + 1; 
    else
        return totalConsonants(str, n - 1); 
} 
  
// Driver code 
public static void main(String args[]) 
{ 
    String str = "abc de"; 
    System.out.println(totalConsonants(str, str.length())); 
} 
} 
  
// This code is contributed by 
// Surendra_Gangwar 

Python3

# Recursive Python3 program to count  
# total number of consonants  
  
# Function to check for consonant 
def isConsonant(ch): 
      
    # To handle lower case 
    ch = ch.upper() 
  
    return not (ch == 'A' or ch == 'E' or 
                ch == 'I' or ch == 'O' or 
                ch == 'U') and ord(ch) >= 65 and ord(ch) <= 90
  
# To count total number of   
# consonants from 0 to n-1 
def totalConsonants(string, n): 
      
    if n == 1: 
        return isConsonant(string[0]) 
  
    return totalConsonants(string, n - 1) + isConsonant(string[n-1]) 
  
  
# Driver code 
string = "abc de"
print(totalConsonants(string, len(string))) 
  
  
# This code is contributed by Ansu Kuamri. 

C#

// Recursive C# program to count  
// total number of consonants  
using System;  
      
class GFG 
{ 
  
// Function to check for consonant 
static Boolean isConsonant(char ch) 
{ 
    // To handle lower case 
    ch = char.ToUpper(ch); 
  
    return (ch == 'A' || ch == 'E' ||  
            ch == 'I' || ch == 'O' ||  
            ch == 'U') == false &&  
            ch >= 65 && ch <= 90; 
} 
  
// to count total number  
// of consonants from 0 to n-1 
static int totalConsonants(String str, int n) 
{ 
    if (n == 1) 
    { 
        if(isConsonant(str[0])) 
            return 1; 
        else
            return 0; 
    } 
      
    if(isConsonant(str[n - 1])) 
        return totalConsonants(str, n - 1) + 1; 
    else
        return totalConsonants(str, n - 1); 
} 
  
// Driver code 
public static void Main(String []args) 
{ 
    String str = "abc de"; 
    Console.WriteLine(totalConsonants(str, str.Length)); 
} 
} 
  
// This code contributed by Rajput-Ji 

Javascript

<script> 
  
// Recursive Javascript program to  
// count total number of consonants  
  
// Function to check for consonant 
function isConsonant(ch) 
{ 
      
    // To handle lower case 
    ch = ch.toUpperCase(); 
      
    return (!(ch == 'A' || ch == 'E' || 
              ch == 'I' || ch == 'O' || 
              ch == 'U') && ch.charCodeAt(0) >= 65 &&  
                            ch.charCodeAt(0) <= 90) ; 
} 
  
// To count total number of consonants from  
// 0 to n-1 
function totalConsonants(str, n) 
{ 
    if (n == 1) 
        return isConsonant(str[0]); 
  
    return totalConsonants(str, n - 1) +  
                isConsonant(str[n - 1]); 
} 
  
// Driver code 
var str = "abc de"; 
  
document.write(totalConsonants(str,str.length)); 
  
// This code is contributed by jana_sayantan 
  
</script>

Output

Time Complexity: O(n), where n is the length of the string
Auxiliary Space: O(n), due to recursive call stacks.

Illustration of recursive method:

Suggest improvement

C++ program to concatenate a string given number of times

Count number of trailing zeros in product of array

Share your thoughts in the comments

Count consonants in a string (Iterative and recursive methods)

C++

Java

Python3

C#

PHP

Javascript

C++

Java

Python3

C#

Javascript

Please Login to comment...

Similar Reads

What kind of Experience do you want to share?