title: Why does map function skip the first element?
body: <p>I was trying to convert alphabets into ASCII using the following:</p>
  
  <pre><code>var subArr = [["S", "E", "R", "R"], ["C", "V", "M", "M", "N", "!"]];
  for (var i in subArr) {
                var newStr = subArr[i].map( function(val) {
                  return val.charCodeAt()
                })
                                           }
  console.log(newStr)       
  </code></pre>
  
  <p>But it seemed that only the second subarray was converted while the first one was not even considered. Would anyone please help me understand the issue here?</p>