Password Validation Program in C++

Hello everyone!

In this tutorial, we will check out how to validate your password using C++ with the corresponding code. We will demonstrate to you how to check whether your password is a strong password or not. For that, we will check whether the password contains at least one uppercase character, one lower case character, and also at least one digit. In General, a strong should be of length more than 6 characters.

Password Validation Program in C++

Steps involved are:-

  1. The user provides the password which is to be check.
  2. The password provided by the user will now be check for uppercase, lowercase, and digits.
  3. The strongness of the password is classified into 3 categories which are, strong, moderate, and weak.
  4. If the password contains all of them then it is considered to be a Strong password.
  5. If the password contains at least an uppercase or lowercase character and at least a digit along with the length of 6 more, then it is considered as a Moderate one.
  6. else it is a weak password.

Below is the C++ code to validate your password:

#include <bits/stdc++.h> 
using namespace std; 
void checkpassword(string& password) 
    int n = password.length();      
    bool hasLower = false, hasUpper = false, hasDigit = false; 
    for (int i = 0; i < n; i++) { 
        if (islower(password[i])) 
            hasLower = true; 
        if (isupper(password[i])) 
            hasUpper = true; 
        if (isdigit(password[i])) 
            hasDigit = true; 
    // Displaying the strength of password 
    cout << "Strength of password you have entered is :-"; 
    if ( hasUpper && hasDigit && hasLower && (n >= 6)) // considering a strong must be of length 6 or more
        cout << "Strong" << endl; 
    else if ((hasLower || hasUpper) && hasDigit && (n >=6)) 
        //when at least a lower case or uppercase is used along with digit
        cout << "Moderate" << endl; 
        cout << "Weak" << endl; 
int main() 
{   cout << "Welcome, lets check your password " << endl;
    cout << "Considering average length of a strong password should be more then 6 character " << endl;
  cout << "Please enter a password which should contain :- " << endl;
  cout << " * at least one upper and lowercase letter " << endl;
  cout << " * and also at least one digit " << endl;
    string password;
    cout <<"Enter password"<<endl;
    return 0; 

Outputs :

Case 1: For Strong password

Enter password


Strength of password you have entered is:-Strong

Case 2: For Moderate password

Enter password


Strength of password you have entered is:-Moderate

Case 3: For Weak password

Enter password


Strength of password you have entered is:-Weak

Similarly, there can be many more inputs for which you can validate your password.

Give it a try.

I hope I have made my point clear. Feel free to ask any query.

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Thank You.

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