package com.neesri.sorting;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
public class ConvertMapToList {
// we can convert Hashmap into Arraylist
through three ways
public static void main(String[] args) {
HashMap<String, Integer> hashmapObj = new HashMap<>();
hashmapObj.put("Zimbabwe", 600);
hashmapObj.put("India", 700);
hashmapObj.put("SriLanka", 400);
hashmapObj.put("Nepal", 800);
// 1-----convert Hashmap Key into List
// using keyset method retun set
view
Set<String> setViewOfMapKeys = hashmapObj.keySet();
// convert set into list
List<String> listObj = new ArrayList<>(setViewOfMapKeys);
System.out.println("Hashmap Keys into
list------>");
for (String printList : listObj) {
System.out.println(printList);
}
// 2. Convert Hashmap Values into List
Collection<Integer> values = hashmapObj.values();
List<Integer> list = new ArrayList<>(values);
System.out.println("Hashmap values into
List----->");
for (Integer hashmapValuesIntoList : list) {
System.out.println(hashmapValuesIntoList);
}
// 3. Convert hashmap all entries into
List
Set<Entry<String, Integer>> entriesObjSet = hashmapObj.entrySet();
List<Entry<String, Integer>> listEntries = new ArrayList<>(entriesObjSet);
// System.out.println("Hashmap all
entries into List======>");
/*
* for(Object obj:listEntries) {
*
* System.out.println(obj); }
*/
// OR
/*
* for(Entry<String, Integer> obj:listEntries)
{
*
* System.out.println(obj); }
*/
// OR
System.out.println("Printing thorough
iterator======>");
Iterator<Entry<String, Integer>> iterator = listEntries.iterator();
while (iterator.hasNext()) {
Entry<String, Integer> entry = iterator.next();
System.out.println(entry);
}
}
}
==============OUTPUT======
Hashmap Keys into list------>
SriLanka
Zimbabwe
Nepal
India
Hashmap values into List----->
400
600
800
700
Printing thorough iterator======>
SriLanka=400
Zimbabwe=600
Nepal=800
India=700
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