Java Programming Language: How to Traverse a HashMap

Hi everyone, welcome back. In this example, we will be going over how to traverse HashMaps in Java. HashMaps can be used to store a collection of data similar to an ArrayList, but the main difference is that HashMaps stores elements as key/value pairs rather than using index numbers. With this introduction out of the way, let’s get into it.

Creating HashMap

Let’s start by creating a HashMap. Before we can create the HashMap, we need to make sure that we have our HashMap import, which is included within the java.util package:

import java.util.HashMap;

Now, we can successfully create our HashMap:

HashMap<Integer, String> myHashMap = new HashMap<Integer, String>();

So now, we have created a HashMap variable. Our key is of the Integer data type and our value is of the String data type. When we create our HashMap, we need to specify the data type of our keys and values. We can use other data types as well for both the key and value.

Adding Elements in the HashMap

Now let’s try to add elements into our HashMap. We can do this by using the built in put() function that is provided. Let’s see an example:

HashMap<Integer, String>…