C++ String Exercises: Extract the first n number of vowels from a string

Last update on April 11 2025 12:48:19 (UTC/GMT +8 hours)

28. Extract a Specified Number of Vowels from a String

A vowel is a syllabic speech sound pronounced without any stricture in the vocal tract. Vowels are one of the two principal classes of speech sounds, the other being the consonant.

Write a C++ program to extract the first specified number of vowels from a given string. If the specified number is less than the number of vowels present in the text, display "n is less than the number of vowels present in the string".

Sample Data:
(“The quick brown fox.”, 2) -> eu
(“CPP Exercises”, 3) -> eie

Sample Solution:

C++ Code:

#include <bits/stdc++.h> // Include all standard libraries

using namespace std; // Using the standard namespace

// Function to extract the first 'n' number of vowels from the input string
string test(string text, int n) {
    string b; // Initialize an empty string 'b' to store extracted vowels
    int k = 0; // Initialize a counter 'k' for the number of extracted vowels

    // Loop through the string to find the first 'n' vowels
    for (int i = 0; i < text.size() && k < n; i++) {
        // Check if the current character is a vowel (a, e, i, o, u)
        if (text[i] == 'a' || text[i] == 'e' || text[i] == 'i' || text[i] == 'o' || text[i] == 'u') {
            k++; // Increment the counter for each found vowel
            b.push_back(text[i]); // Append the vowel to the 'b' string
        }
    }

    // Check if 'n' is less than the number of vowels found in the string
    if (k < n) {
        return "n is less than the number of vowels present in the string!";
    } else {
        return b; // Return the extracted vowel string 'b'
    }
}

int main() {
    string text; // Declare a string variable to store user input
    int n; // Declare an integer variable to store user input for 'n'

    cout << "Input a string: ";
    getline(cin, text); // Input a string from the user

    cout << "Input a number: ";
    cin >> n; // Input an integer from the user

    cout << "\nExtract the first n number of vowels from the said string:\n";
    cout << test(text, n) << endl; // Output the extracted vowels or a message indicating insufficient vowels
}

Sample Output:

Input a string: Input a number: 
Extract the first n number of vowels from the said string:
n is less than number of vowels present in the string!

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program to extract the first n vowels from a string, and if n exceeds the count, display a message.
• Write a C++ program that reads a string and a number, then outputs the first n vowels found, or an error if insufficient vowels.
• Write a C++ program to count the vowels in a string and extract them into a new string if the specified count is less than available.
• Write a C++ program to scan a string and return the first n vowels, alerting the user if n is larger than the total vowels present.

C++ Code Editor:

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