Practice›Java Fundamentals›Module 10. Collections›10.1 HashMap

Task 4 of 9 · 0 solved · 9 to go0%

1 2 345 6 7 8 9

You can read the problem, but answers are checked only for signed-in students. Sign in to answer →

10.1 HashMap — count present keys

Total: 0 / 3 pts

Practice mode — check each part and get hints as you go.

Task

Fill in countPresent so that it returns how many of the given strings are keys of the map. Use containsKey.

The program prints 2.

Your solution

import java.util.HashMap;
import java.util.Map;

public class Main {

    public static int countPresent(Map<String, Integer> m, String[] keys) {
        // count how many of the keys are in the map

    }

    public static void main(String[] args) {
        Map<String, Integer> m = new HashMap<String, Integer>();
        m.put("Ada", 30);
        m.put("Sam", 25);
        System.out.println(countPresent(m, new String[]{"Ada", "Bo", "Sam"}));
    }
}

Next task →