title: Matrix size Java
body: <p>I have a matrix for example 5x10.</p>
  
  <pre><code>double[][] matrix = new double[5][10]
  </code></pre>
  
  <p>I would like to know the size of these matrix, But if I do it:</p>
  
  <pre><code>matrix.length
  </code></pre>
  
  <p>It only return me columns size: 10</p>
  
  <p>How could I do it?</p>