LESSON 171 OF 413 · PROJECTS: EVERYDAY PROGRAMS

Password Strength V5 - Common Password Dictionary in C#

Practice

Use a dictionary (or set) as a fast lookup table to reject well-known weak passwords.

You start with:

HashSet<string> common = new HashSet<string> { "password", "123456", "qwerty", "letmein" };
string password = "qwerty";

Build:

Password: qwerty
Common: True
Weak: reject

Rules:

Print "Password: " followed by the password.
Look the password up in the set common and store the result as a boolean.
Print "Common: " followed by the boolean. Write it as True or False with a capital letter, exactly as in the example (your language's own boolean prints differently, so choose the text yourself).
If it is common, print "Weak: reject"; otherwise print "Strong: accept".

Try other passwords: with Tr0ub4dor the output is

Password: Tr0ub4dor
Common: False
Strong: accept

Use a HashSet<string> and call .Contains(password).

HashSet<string> common = new HashSet<string> { "password", "123456", "qwerty", "letmein" };
string password = "qwerty";

Console.WriteLine("Password: " + password);
bool isCommon = common.Contains(password);
Console.WriteLine("Common: " + (isCommon ? "True" : "False"));
if (isCommon) {
    Console.WriteLine("Weak: reject");
} else {
    Console.WriteLine("Strong: accept");
}

STEP 1 OF 5

Guided

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Password Strength V5 - Common Password Dictionary in C#

Password Strength V5 in C#