title: Bad output after split and map
body: <p>I run following code and javascript return crazy resualt?</p>
  
  <p>code:</p>
  
  <p><code>"000000000000000000000000".split('').map(parseInt)</code></p>
  
  <p>output: </p>
  
  <p><code>[0, NaN, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]</code></p>
  
  <p>why second item of array is NaN?</p>