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import java.util.HashMap;
public class HashMapExample {
public static void main(final String[] args) {
HashMap<String, Double> hm = new HashMap<>();
// Insert three elements
hm.put("John", 1.0);
hm.put("Mary", 3.0);
hm.put("Jane", 2.0);
System.out.println(hm); // print all entries
hm.remove("Jane"); // remove an entry
System.out.println(hm); // print all entries
// Lookup based on key
System.out.println("John: " + hm.get("John"));
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