title: Map<String, String>, how to print both the "key string" and "value string" together
body: <p>I'm new to Java and is trying to learn the concept of Maps. </p>
  
  <p>I have came up with the code below. However, I want to print out the "key String" and "value String" at the same time. </p>
  
  <pre><code>ProcessBuilder pb1 = new ProcessBuilder();
  Map&lt;String, String&gt; mss1 = pb1.environment();
  System.out.println(mss1.size());
  
  for (String key: mss1.keySet()){
      System.out.println(key);
  }
  </code></pre>
  
  <p>I could only find method that print only the "key String".</p>