Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

public class Main {
    public static void main(String args[]) {
        Map<String, Integer> atomNums = new TreeMap<String, Integer>();

        atomNums.put("A", 1);
        atomNums.put("B", 2);
        atomNums.put("C", 3);
        atomNums.put("D", 4);
        atomNums.put("E", 5);
        atomNums.put("F", 6);

        System.out.println("The map contains these " + atomNums.size() + " entries:");

        Set<Map.Entry<String, Integer>> set = atomNums.entrySet();

        for (Map.Entry<String, Integer> me : set) {
            System.out.print(me.getKey() + ", Atomic Number: ");
            System.out.println(me.getValue());
        }
        TreeMap<String, Integer> atomNums2 = new TreeMap<String, Integer>();

        atomNums2.put("Q", 30);
        atomNums2.put("W", 82);

        atomNums.putAll(atomNums2);

        set = atomNums.entrySet();

        System.out.println("The map now contains these " + atomNums.size() + " entries:");
        for (Map.Entry<String, Integer> me : set) {
            System.out.print(me.getKey() + ", Atomic Number: ");
            System.out.println(me.getValue());
        }

        if (atomNums.containsKey("A"))
            System.out.println("A has an atomic number of " + atomNums.get("A"));

        if (atomNums.containsValue(82))
            System.out.println("The atomic number 82 is in the map.");
        System.out.println();

        if (atomNums.remove("A") != null)
            System.out.println("A has been removed.\n");
        else
            System.out.println("Entry not found.\n");

        Set<String> keys = atomNums.keySet();
        for (String str : keys)
            System.out.println(str + " ");

        Collection<Integer> vals = atomNums.values();
        for (Integer n : vals)
            System.out.println(n + " ");

        atomNums.clear();
        if (atomNums.isEmpty())
            System.out.println("The map is now empty.");
    }
}