MainClass.java Source code

Introduction

Here is the source code for MainClass.java

Source

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

public class MainClass {
    public static void main(String[] a) {
        Map map = new HashMap();
        map.put("key1", "value1");
        map.put("key2", "value2");
        map.put("key3", "value3");
        map.put(null, null);

        Set set = map.keySet();

        Iterator iter = set.iterator();

        while (iter.hasNext()) {
            System.out.println(iter.next());
        }
    }
}