Desperate Attempt #2

Question about the task

Under discussion

Create a Map<String, String> and add ten entries that represent (last name, first name) pairs.
Remove people with the same first name.

Requirements:

The program should not display text on the screen.
The program should not read values from the keyboard.
The createMap() method must create and return a HashMap that has (String, String) elements and contains 10 entries.
The removeFirstNameDuplicates() method must remove from the map all people who have the same first name.
The removeFirstNameDuplicates() method must call the removeItemFromMapByValue() method.

package com.codegym.task.task08.task0817; import java.util.HashMap; import java.util.Map; import java.util.ArrayList; /* We don't need repeats */ public class Solution { public static HashMap<String, String> createMap() { //write your code here HashMap<String, String> names = new HashMap<>(); names.put("John", "Doe"); names.put("John1", "Doe1"); names.put("John2", "Doe2"); names.put("John3", "Doe3"); names.put("John4", "Doe4"); names.put("John5", "Doe"); names.put("John6", "Doe1"); names.put("John7", "Doe2"); names.put("John8", "Doe3"); names.put("John9", "Doe4"); return names; } public static void removeFirstNameDuplicates(Map<String, String> map) { //write your code here HashMap<String, String> cloneMap = new HashMap<String, String>(map); map.clear(); for (Map.Entry<String, String> kv : cloneMap.entrySet()) { if (!map.containsValue(kv.getValue())) { map.put(kv.getKey(), kv.getValue()); } else { removeItemFromMapByValue(map, kv.getValue()); } } } public static void removeItemFromMapByValue(Map<String, String> map, String value) { HashMap<String, String> copy = new HashMap<String, String>(map); for (Map.Entry<String, String> pair : copy.entrySet()) { if (pair.getValue().equals(map.values())) map.remove(pair.getKey()); } } public static void main(String[] args) { //removeFirstNameDuplicates(createMap()); } }

Comments (2)

Popular
New
Old

You must be signed in to leave a comment

Guadalupe Gagnon

Level 37 , Tampa, United States

17 March 2019, 15:25

It is probably failing because the verification system may be checking 'map' as the code runs. If this is the case then when you clear it at line 33 verification is probably automatically failing. Try replacing line 33 with creating a HashSet<String>. Then in the for each loop, use the same logic with the new HashSet instead of 'map' (checking if the set contains the value and adding it if it does not).

// Java Poser

Level 18 , Cincinnati, United States

18 March 2019, 00:44

Thank you very much Guadalupe, I finally figured it out. took me a few days lmao