Java Collection How to - Convert List to Hashmap using the index as key

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Question

We would like to know how to convert List to Hashmap using the index as key.

Answer

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
//w w w .  j ava  2  s.c om
public class Main {
  public static void main(String[] args) {
    List<String> aList = new ArrayList<String>();
    Map<Integer, String> aMap = new HashMap<Integer, String>();
    aList.add("A");
    aList.add("B");
    
    for (int i = 0; i < aList.size(); i++) {
      aMap.put(i + 1, aList.get(i));
    }
    
    System.out.println(aMap.toString());
  }
}

The code above generates the following result.

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