title: Float arithemtic and double precision?
body: <p>I was confused by the difference between <code>float</code> and <code>double</code>. I read <a href="https://stackoverflow.com/q/21895756/4671213">this post</a>. I thought the the difference is just in precision. So I expected that if <code>0.1 + 0.2 == 0.3</code> returns <code>false</code> then either does <code>0.1f + 0.2f == 0.3f</code>. </p>
  
  <p>But actually <code>0.1f + 0.2f == 0.3f</code> returns <code>true</code>. Why that?</p>
  
  <p>Is that a pure Java issue or what?</p>