title: Java, quickest way to determine if any values in hashmap match a value?
body: <p>Pardon my newbie-ness to Java as I am not experienced enough to know the most efficient way to do this. I have a hashmap like below, but it would have like 40,000 entries:</p>
  
  <pre><code>Map &lt;String, String&gt; someHashmap = new HashMap &lt;String, String&gt; ();
  someHashmap.put("filepath1", null);
  someHashmap.put("filepath2", "tag1");
  someHashmap.put("filepath3", "tag2");
  </code></pre>
  
  <p>I want to determine how many value match <code>null</code> so that I can determine if any are null. Of course I could do a regular loop to check but am wondering if there is a more efficient way, thanks</p>