LESSON 168 OF 410 · PROJECTS: EVERYDAY PROGRAMS

Password Strength V5 - Common Password Dictionary in Java

Practice

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

You start with:

Set<String> common = new HashSet<>(Arrays.asList("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 Set<String> built from Arrays.asList(...) and call .contains(password).

Set<String> common = new HashSet<>(Arrays.asList("password", "123456", "qwerty", "letmein"));
String password = "qwerty";

System.out.println("Password: " + password);
boolean isCommon = common.contains(password);
System.out.println("Common: " + (isCommon ? "True" : "False"));
if (isCommon) {
    System.out.println("Weak: reject");
} else {
    System.out.println("Strong: accept");
}

STEP 1 OF 5

Guided

Ctrl + Enter to check

Password Strength V5 - Common Password Dictionary in Java

Password Strength V5 in Java