Static Interface Methods

Lab Java Intermediate 20 points

Create interface Validator with boolean isValid(String s) and a Java 8 static Validator minLength(int n) factory plus a default Validator and(Validator other). Validate passwords against min length 8 and contains a digit.

Input

n, then n passwords.

Output

n lines: ok or weak.

Example

Input

3
password1
short1
nodigitshere

Output

ok
weak
weak

Sample input available Sample output available

Editor

Java

Hints

A lambda can implement any interface with one abstract method.

default methods can combine instances.

Solution explanation

Small composable validators like this are how Java 8 APIs such as Comparator and Predicate are designed.

Show solution

import java.util.Scanner;

interface Validator {
    boolean isValid(String s);

    static Validator minLength(int n) {
        return s -> s.length() >= n;
    }

    default Validator and(Validator other) {
        return s -> isValid(s) && other.isValid(s);
    }
}

public class Main {
    public static void main(String[] args) {
        Validator hasDigit = s -> s.chars().anyMatch(Character::isDigit);
        Validator strong = Validator.minLength(8).and(hasDigit);
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        for (int i = 0; i < n; i++) {
            System.out.println(strong.isValid(sc.next()) ? "ok" : "weak");
        }
    }
}

Output

Answer