title: Difference between the == and %in% operators in R
body: <p>My question concerns the practical difference between the <code>==</code> and <code>%in%</code> operators in R.</p>
  
  <p>I have run into an instance at work where filtering with either operator gives different results (e.g. one results on 800 rows, and the other 1200). I have run into this problem in the past and am able to validate in a way that ensures I get the results I desire. However, I am still stumped regarding how they are different.</p>
  
  <p>Can someone please shed some light on how these operators are different?   </p>