title: How to iterate over an array skipping every second element?
body: <p>How to write this type of for loop in ruby?</p>
  
  <pre><code>for(i = 0; i &lt; arr.length; i = i+2) {
  }
  </code></pre>
  
  <p>I know how to write it if step is 1, but if step > 1, how to make it?</p>