function findLongestWord(str) {
  //Make string into array, with each word as an array value
  var strArray = str.split(" ");
  //Create variable to hold value of longest word
  var longestWord = 0;
  //Iterate through the array and find the length of each value to determine longest word
  for (var i = 0; i < strArray.length; i++) {
    if (strArray[i].length > longestWord) {
      longestWord = strArray[i].length;
    }
  }
  return longestWord;
}

findLongestWord("The quick brown fox jumped over the lazy dog");