Math_Learning/src/Base/User.java

package Base;

public class User {
    private String email;
    private String password;


    public User(String email) {
        this.email = email;
    }

    public String get_email() { return email; }
    public String get_password() { return password; }
    public void set_password(String password) { this.password = password; }

    public static boolean check_password(String password) {
        if (password == null || password.length() < 6 || password.length() > 20) {
            return false;
        }

        boolean hasUpper = false;
        boolean hasLower = false;
        boolean hasDigit = false;

        for (char c : password.toCharArray()) {
            if (Character.isUpperCase(c)) hasUpper = true;
            if (Character.isLowerCase(c)) hasLower = true;
            if (Character.isDigit(c)) hasDigit = true;
        }
        return hasUpper && hasLower && hasDigit;
    }
}