Program to count the number of consonants in a word

Write a program to count the number of consonants in a given word. Consonants are the letters of the English alphabet excluding vowels (‘a’, ‘e’, ‘i’, ‘o’, ‘u’).

Examples:

Input: “programming”
Output: 8
Explanation: The eight consonants are: ‘p’, ‘r’, ‘g’, ‘r’, ‘m’, ‘m’, ‘n’, ‘g’)

Input: “hello”
Output: 3
Explanation: There are three consonants: ‘h’, ‘l’, ‘l’

Approach: To solve the problem, follow the below idea:

The problem can be solved by iterating through the entire word character by character and for each character, check if the character is a vowel. If the character is ‘a’ or ‘e’ or ‘i’ or ‘o’ or ‘u’, then it is a vowel otherwise it is a consonant. If the character is a consonant, increment the answer by 1.

Step-by-step algorithm:

• Initialize a variable to store the count of consonants.
• Iterate through each character in the word.
• Check if the character is a consonant (not a vowel).
• If it is a consonant, increment the count.
• Print the final count.

Below is the implementation of the approach:

C++

#include <iostream>

using namespace std;

// function to check whether ch is a lowercase alphabet or
// not
bool isLowerCaseAlphabet(char ch)
{
    return ch >= 'a' && ch <= 'z';
}

// function to check whether ch is a lowercase vowel or not
bool isVowel(char ch)
{
    return ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o'
           || ch == 'u';
}

int main()
{

    string word = "programming";
    int consonantCount = 0;

    for (int i = 0; i < word.length(); ++i) {
        // Convert to lowercase for case-insensitivity
        char ch = tolower(word[i]);
        if (isLowerCaseAlphabet(ch) && !isVowel(ch)) {
            consonantCount++;
        }
    }

    cout << "Number of consonants: " << consonantCount
         << endl;

    return 0;
}

C

#include <stdio.h>

// function to check whether ch is a lowercase alphabet or not
int isLowerCaseAlphabet(char ch)
{
    return (ch >= 'a' && ch <= 'z');
}

// function to check whether ch is a lowercase vowel or not
int isVowel(char ch)
{
    return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o'
            || ch == 'u');
}

int main()
{
    char word[] = "programming";
    int consonantCount = 0;

    for (int i = 0; i < strlen(word); ++i) {
        // Convert to lowercase for case-insensitivity
        char ch = tolower(word[i]);
        if (isLowerCaseAlphabet(ch) && !isVowel(ch)) {
            consonantCount++;
        }
    }

    printf("Number of consonants: %d\n", consonantCount);

    return 0;
}

Java

public class ConsonantCounter {
    // function to check whether ch is a lowercase alphabet
    // or not
    static boolean isLowerCaseAlphabet(char ch)
    {
        return ch >= 'a' && ch <= 'z';
    }

    // function to check whether ch is a lowercase vowel or
    // not
    static boolean isVowel(char ch)
    {
        return ch == 'a' || ch == 'e' || ch == 'i'
            || ch == 'o' || ch == 'u';
    }

    public static void main(String[] args)
    {
        String word = "programming";
        int consonantCount = 0;

        for (int i = 0; i < word.length(); ++i) {
            // Convert to lowercase for case-insensitivity
            char ch = Character.toLowerCase(word.charAt(i));
            if (isLowerCaseAlphabet(ch) && !isVowel(ch)) {
                consonantCount++;
            }
        }

        System.out.println("Number of consonants: "
                           + consonantCount);
    }
}

Python3

def is_lower_case_alphabet(ch):
    return 'a' <= ch <= 'z'

def is_vowel(ch):
    return ch in {'a', 'e', 'i', 'o', 'u'}

word = "programming"
consonant_count = 0

for i in range(len(word)):
    # Convert to lowercase for case-insensitivity
    ch = word[i].lower()
    if is_lower_case_alphabet(ch) and not is_vowel(ch):
        consonant_count += 1

print("Number of consonants:", consonant_count)

C#

using System;

class Program {
    // Function to check whether ch is a lowercase alphabet
    // or not
    static bool IsLowerCaseAlphabet(char ch)
    {
        return ch >= 'a' && ch <= 'z';
    }

    // Function to check whether ch is a lowercase vowel or
    // not
    static bool IsVowel(char ch)
    {
        return ch == 'a' || ch == 'e' || ch == 'i'
            || ch == 'o' || ch == 'u';
    }

    static void Main()
    {
        string word = "programming";
        int consonantCount = 0;

        for (int i = 0; i < word.Length; ++i) {
            // Convert to lowercase for case-insensitivity
            char ch = char.ToLower(word[i]);
            if (IsLowerCaseAlphabet(ch) && !IsVowel(ch)) {
                consonantCount++;
            }
        }

        Console.WriteLine("Number of consonants: "
                          + consonantCount);
    }
}

Javascript

// Function to check whether ch is a lowercase alphabet or not
function isLowerCaseAlphabet(ch) {
    return ch >= 'a' && ch <= 'z';
}

// Function to check whether ch is a lowercase vowel or not
function isVowel(ch) {
    return ch === 'a' || ch === 'e' || ch === 'i' || ch === 'o' || ch === 'u';
}

let word = "programming";
let consonantCount = 0;

for (let i = 0; i < word.length; ++i) {
    // Convert to lowercase for case-insensitivity
    let ch = word[i].toLowerCase();
    if (isLowerCaseAlphabet(ch) && !isVowel(ch)) {
        consonantCount++;
    }
}

console.log("Number of consonants: " + consonantCount);

Output

Number of consonants: 8

Time Complexity: O(N) where N is the length of the word.
Auxiliary Space: O(1) (constant space is used)