Password program

[Unisaurus]

Okie dokie I have to write a program that takes a password and makes sure it has 8 characters, 1 capital, and 1 lowercase letter.

Now I know I'm close. I can get two or three different passwords to work and than some just don't. Any help is appreciated! Please explain with suggestions, my professor is not that great. Thank you!

#include <iostream>
#include <cctype>
#include <string>

using namespace std;


int main()
{


	const int length = 8;
	int password[length];

	cout << "Please enter a password: " << endl;
	cin >> password[length];




	{


		int i = 0;
		int big = 0; // counter for big
		int lil = 0; // counter for little
		bool valid = false;

		while (i > password[length])

		{

			if (password[length] >= 'a' && password[length] <= 'z')

			{

				lil++;

			}
			else
			{
				
				if (password[length] >= 'A' && password[length] <= 'Z')
				{



				}

				else
				{

					big++;

				}

			}
			

			i++;
		}








		if (8 >= password[length])
		{
			
		}
		else
		{

			cout << "You need to have at least 8 characters in your password." << endl;

		}

		if (big == password[length])
		{
			
			cout << "You need at least one Uppercase letter." << endl;

		}

		else
		{

			
			if (lil == password[length])
			{

				cout << "You need to have at least one Lowercase letter." << endl;
				
			}
			else
			{

				

			}

		}
		
		if (valid = password[length])
		{

			

		}
		else
		{

			cout << "Thank you, that is a valid password!" << endl;

		}
	}

		




		system("pause");
		return 0;

	
}

[JLBorges]

#include <iostream>
#include <string> // https://cal-linux.com/tutorials/strings.html
#include <cctype> // http://en.cppreference.com/w/cpp/header/cctype

int num_alpha_chars( std::string str )
{
    int num_alpha = 0 ;
    for( char c : str ) if( std::isalpha(c) ) ++num_alpha ;
    return num_alpha ;
}

bool has_lower_case_char( std::string str )
{
    // http://www.stroustrup.com/C++11FAQ.html#for
    for( char c : str ) if( std::islower(c) ) return true ;
    return false ;
}

bool has_upper_case_char( std::string str )
{
    for( char c : str ) if( std::isupper(c) ) return true ;
    return false ;
}

int main()
{
    std::string pword ;
    std::cout << "password? " ;
    std::getline( std::cin, pword ) ; // or std::cin >> pword if spaces are not allowed

    if( num_alpha_chars(pword) < 8 ) std::cout << "at least 8 alpha characters are required.\n" ;
    else if( !has_lower_case_char(pword) ) std::cout << "there must be at least one lower case character\n" ;
    else if( !has_upper_case_char(pword) ) std::cout << "there must be at least one upper case character\n" ;
    else std::cout << "that is a valid password\n" ;
}

[littlepig]

there are some logic errors in your code. this version works

int main()
{
    const int PASSWORD_MAX = 1024;
    char password[PASSWORD_MAX];
    cout << "Please enter a password: " << endl;
    std::cin.getline(password, sizeof(password));
    {
        int i = 0;
        int big = 0; // counter for big
        int lil = 0; // counter for little
        bool valid = true;

        for (int i = 0; i < strnlen(password, sizeof(password)); i++)
        {
            if (password[i] >= 'a' && password[i] <= 'z')
            {
                lil++;
            }
            else if (password[i] >= 'A' && password[i] <= 'Z')
            {
                big++;
            }
        }

        if (8 > strnlen(password, sizeof(password)))
        {
            cout << "You need to have at least 8 characters in your password." << endl;
            valid = false;
        }

        if (big == 0)
        {
            cout << "You need at least one Uppercase letter." << endl;
            valid = false;
        }

        if (lil == 0)
        {
            cout << "You need to have at least one Lowercase letter." << endl;
            valid = false;
        }

        if (valid)
        {
            cout << "Thank you, that is a valid password!" << endl;
        }
        else
        {
            cout << "invalid password!" << endl;
        }
    }
    system("pause");
    return 0;
}

this is my version

bool check_password(const std::string password)
{
    // make sure it has at lease 8 characters
    if (password.size() < 8)
    {
        std::cout << "you need to have at lease 8 charaters" << std::endl;
        return false;
    }

    int numOfCapital = 0;
    int numOfLowerCase = 0;

    for (char c : password)
    {
        if (c >= 'a' && c <= 'z')
        {
            numOfLowerCase++;
        }

        if (c >= 'A' && c <= 'Z')
        {
            numOfCapital++;
        }
    }

    // make sure it has at lease one capital
    if (numOfCapital < 1)
    {
        std::cout << "you need to have at lease one capital letter" << std::endl;
        return false;
    }

    // make sure it has at least one lowercase
    if (numOfLowerCase < 1)
    {
        std::cout << "you need to have at least one lower case letter" << std::endl;
        return false;
    }

    return true;
}

int main()
{
    char password[256];   //8 characters, plus '\0' for teminating
    std::cin.getline(password, sizeof(password));
    bool valid = check_password(std::string(password));

    if (valid)
    {
        std::cout << "password is valid" << std::endl;
    }
    else
    {
        std::cout << "password is invalid!" << std::endl;
    }

    system("pause");
    return 0;
}

[Unisaurus]

Thank y'all so much for the help! Definitely had a few hunches about some of the code and should have acted on them, because they turned out right!