I don't know how to use the required method and do this differently?

Question about the task

We don't need repeats

Java Syntax, Level 8, Lesson 8

Resolved

Can someone help or guide me?

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.Iterator; import java.util.Map; /* We don't need repeats */ public class Solution { public static HashMap<String, String> createMap() { HashMap<String, String> map = new HashMap<>(); map.put("Tranberg", "Anita"); map.put("Tranberg1", "Anita"); map.put("Al-Saffar", "Anders"); map.put("Luiz", "Anders"); map.put("Tranberg2", "Allan"); map.put("Tranberg3", "Katrine"); map.put("Tranberg4", "Katrine"); map.put("Tranberg5", "Else"); map.put("Tranberg6", "Jens"); map.put("Sørensen", "Henrik"); return map; } public static void removeFirstNameDuplicates(Map<String, String> map) { HashMap<String, String> copy = new HashMap<String, String>(map); for (Map.Entry<String, String> pair : copy.entrySet()) { String firstName = pair.getValue(); int nameCount = 0; Iterator<Map.Entry<String, String>> iterator = copy.entrySet().iterator(); while (iterator.hasNext()) { Map.Entry<String, String> pair2 = iterator.next(); if (pair2.getValue().equals(firstName)) nameCount++; if (nameCount > 1) { map.remove(pair2.getKey()); nameCount = 1; } } } } 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(value)) map.remove(pair.getKey()); } } public static void main(String[] args) { removeFirstNameDuplicates(createMap()); } }

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Joe M

Level 47 , Owings Mills, United States

3 January 2021, 22:47

good work AM , I dont understand this. Your work and commments are helpful. Thank you Guadelupe!

Anitamalina

Level 18 , København, Denmark

18 December 2020, 19:09

Thanks! I realized I also read the task wrong. Thought I shouldn't remove all duplicates, but keep 1. But thank you! :)

Guadalupe Gagnon

Level 37 , Tampa, United States

18 December 2020, 17:52

solution

Consider the parameters of the method, they are on line 51 and named: (map, value) You are going to have to pass the correct arguments to that method. You should know the correct map that you want to remove items from, you are doing so already with your code. Inferring what should be passed for value shouldn't be hard to figure out either because the word "value" appears in some form in a couple places of your code already. There is one line where you are removing items from the map, which would be the correct spot to call that method from. Try it out. It is not difficult.