coderbyte reversing string

gistfile1.txt

function FirstReverse(str) { 

  // code goes here
  str = "change string content here";
  //array is defining str.split as array, the .split object is splitting str into individual letters
   array = str.split("");
   //.reverse object is taking the array that we just made and reversing its order
    array.reverse();
    //array.join('') combines the string with the array without commas
    str = array.join('');
     return str; 
         
}
   var array;
   
// keep this function call here 
FirstReverse(readline());   

This looks good.
One small note on terminology: split and reverse are better described as functions or methods than objects.