HashMap : HashTable Map « Collections Data Structure « Java


import java.util.HashMap;
import java.util.Map;
import java.util.Set;

class HashMapDemo {
  public static void main(String args[]) {

    HashMap<String, Double> hm = new HashMap<String, Double>();

    hm.put("A", new Double(3.34));
    hm.put("B", new Double(1.22));
    hm.put("C", new Double(1.00));
    hm.put("D", new Double(9.22));
    hm.put("E", new Double(-19.08));

    Set<Map.Entry<String, Double>> set = hm.entrySet();

    for (Map.Entry<String, Double> me : set) {
      System.out.print(me.getKey() + ": ");

    double balance = hm.get("A");
    hm.put("A", balance + 1000);



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