Remove the vowels from a string in C++

Understanding Vowel Removal

Vowel removal involves deleting all vowels (a, e, i, o, u) from a given string.

We will explore three different methods to remove vowels from a string using C++.

Method 1: Using a Loop

This method iterates through the string and constructs a new string without vowels.

#include <iostream>
#include <string>
using namespace std;

void removeVowels(string str) {
    string result = "";
    for (char c : str) {
        if (string("aeiouAEIOU").find(c) == string::npos) {
            result += c;
        }
    }
    cout << "String without vowels: " << result << endl;
}

int main() {
    string str;
    cout << "Enter a string: ";
    getline(cin, str);
    removeVowels(str);
    return 0;
}
            

Method 2: Using Recursion

This method removes vowels recursively.

#include <iostream>
#include <string>
using namespace std;

void removeVowelsRecursive(string &str, int index) {
    if (index >= str.length()) return;
    if (string("aeiouAEIOU").find(str[index]) != string::npos) {
        str.erase(index, 1);
        removeVowelsRecursive(str, index);
    } else {
        removeVowelsRecursive(str, index + 1);
    }
}

int main() {
    string str;
    cout << "Enter a string: ";
    getline(cin, str);
    removeVowelsRecursive(str, 0);
    cout << "String without vowels: " << str << endl;
    return 0;
}
            

Method 3: Using Pointers

This method uses pointer manipulation to remove vowels.

#include <iostream>
#include <string>
using namespace std;

void removeVowelsPointer(string &str) {
    string result = "";
    for (char *ptr = &str[0]; *ptr; ptr++) {
        if (string("aeiouAEIOU").find(*ptr) == string::npos) {
            result += *ptr;
        }
    }
    str = result;
    cout << "String without vowels: " << str << endl;
}

int main() {
    string str;
    cout << "Enter a string: ";
    getline(cin, str);
    removeVowelsPointer(str);
    return 0;
}