java - Iterating over hashmap

I've written the following piece of code and am stuck on iterating over the hashmap.

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

class demo

{
    public static void main(String v[]) {
        ArrayList contactIds = new ArrayList();
        contactIds.add("2");
        contactIds.add("3");

        HashMap names = new HashMap();
        names =  getNames(contactIds);

        // I want to get the total size of the hashmap  - names

        // for ex now there are 6 elements inside hashmap.
        // How can I get that count?

    }


    private static HashMap getNames(ArrayList contactIds) {
        HashMap names = new HashMap();
        String params = null;
        List list = new ArrayList();

        for(int i=0; i            params = contactIds.get(i).toString();

            list.add(0,"aer-1");
            list.add(1,"aer-2");
            list.add(2,"aer-3");

            names.put(params,list) ;
         }


        return names;
    }
}

In this code, there are six elments inside the map, now in the main method how can I iterate over the map and get the total count?

Thank you.

Answer

Your question is asked - and answered - here:

How to efficiently iterate over each Entry in a Map?

for (Map.Entry entry : map.entrySet()) {
    System.out.println(entry.getKey() + "/" + entry.getValue());
}