title: Use of JsonIgnoreProperties specific property deserialize properties exists only in JSON
body: <p>I stumbled upon some code that adds <a href="https://fasterxml.github.io/jackson-annotations/javadoc/2.6/com/fasterxml/jackson/annotation/JsonIgnoreProperties.html" rel="nofollow noreferrer">JsonIgnoreProperties</a> to a property that doesn't exists in class, but exists in <code>JSON</code>, e.g.:</p>
  <pre><code>@JsonIgnoreProperties({&quot;ignoreprop&quot;})
  public class VO {
     public String prop;
  }
  </code></pre>
  <p>When <code>JSON</code> is</p>
  <pre><code>{ &quot;prop&quot;:&quot;1&quot;, &quot;ignoreprop&quot;:&quot;9999&quot;}
  </code></pre>
  <p>I wonder if ignoring properties has any advantage(s) performance-wise or is it just redundant code?</p>
  <blockquote>
  <p>Annotation that can be used to either suppress serialization of properties (during serialization), or ignore processing of JSON properties read (during deserialization).</p>
  </blockquote>
  <p><strong>EDIT</strong></p>
  <p>Is there an advantage(s) ignoring specific property over all (with
  <code>@JsonIgnoreProperties(ignoreUnknown=true)</code>)?</p>