title: Ruby : How to compare 2 arrays of string
body: <p>I have 2 arrays of strings as under. I want to compare them and execute some code if these arrays are not equal-</p>
  
  <pre><code>current_instances  = ["170601_7711", "170601_8811"]
  app_instances      = ["170602_7711", "170602_8811"]
  </code></pre>
  
  <p>How can I compare them in ruby?</p>