title: Extending custom classes and using them in Java
body: <p>I'm just learning Java... I have 2 custom classes. One is a <code>Fraction</code> and another is a <code>Matrice</code> that uses <code>Fraction</code>.<br>
  I'm using Eclipse, and created both classes from scratch via <code>file-&gt;new-&gt;class</code> (and default settings).</p>
  
  <p>I'm wondering how can I use these two together in my main program? Like, when I try to add the classes to my project (it was unsuccessful but also) the <code>Matrice</code> class broke.</p>
  
  <p>I also put the <code>Fractions</code> class (.class and .java) in a higher hierarchy of directories with no success (put <code>Fractions</code> in <code>com.myfolder</code> and <code>Matrices</code> in <code>com.myfolder.myotherfolder</code> and specified <code>package com.myfolder</code> and <code>package com.myfolder.myotherfolder</code> respectively). </p>
  
  <p>So really, I have no idea what I'm doing here. I'm doing Java on my own, so I get stuck on a lot of the things like this. My question is, how do I: </p>
  
  <ol>
  <li>Make real classes I can use in the future (object classes or whatever you call them; like I would call a new instance of <code>Fraction</code>/<code>Matrice</code>),</li>
  <li>Make custom classes that extend other custom classes,</li>
  <li>Use my custom classes in a project.</li>
  </ol>
  
  <p>I've googled it but had no luck. Many thanks in advance. </p>