4.FindLongestWordLength.js

function findLongestWord(str) {
  // Step 1. Split the string into an array of strings
  var strSplit = str.split(' ');
  // var strSplit = "The quick brown fox jumped over the lazy dog".split(' ');
  // var strSplit = ["The", "quick", "brown", "fox", "jumped", "over", "the", "lazy", "dog"];
	
  // Step 2. Initiate a variable that will hold the length of the longest word
  var longestWord = 0;

  // Step 3. Create the FOR loop
  for(var i = 0; i < strSplit.length; i++){
    if(strSplit[i].length > longestWord){ // If strSplit[i].length is greater than the word it is compared with...
	longestWord = strSplit[i].length; // ...then longestWord takes this new value
     }
  }
  /* Here strSplit.length = 9
     For each iteration: i = ?   i < strSplit.length?   i++  if(strSplit[i].length > longestWord)?   longestWord = strSplit[i].length
     1st iteration:        0             yes             1   if("The".length > 0)? => if(3 > 0)?     longestWord = 3
     2nd iteration:        1             yes             2   if("quick".length > 3)? => if(5 > 3)?   longestWord = 5   
     3rd iteration:        2             yes             3   if("brown".length > 5)? => if(5 > 5)?   longestWord = 5   
     4th iteration:        3             yes             4   if("fox".length > 5)? => if(3 > 5)?     longestWord = 5  
     5th iteration:        4             yes             5   if("jumped".length > 5)? => if(6 > 5)?  longestWord = 6 
     6th iteration:        5             yes             6   if("over".length > 6)? => if(4 > 6)?    longestWord = 6 
     7th iteration:        6             yes             7   if("the".length > 6)? => if(3 > 6)?     longestWord = 6
     8th iteration:        7             yes             8   if("lazy".length > 6)? => if(4 > 6)?    longestWord = 6 
     9th iteration:        8             yes             9   if("dog".length > 6)? => if(3 > 6)?     longestWord = 6 
     10th iteration:       9             no               
     End of the FOR Loop*/

  //Step 4. Return the longest word
  return longestWord; // 6
}

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

//WithoutComments
function findLongestWord(str) {
  var strSplit = str.split(' ');
  var longestWord = 0;
  for(var i = 0; i < strSplit.length; i++){
    if(strSplit[i].length > longestWord){
	longestWord = strSplit[i].length;
     }
  }
  return longestWord;
}
findLongestWord("The quick brown fox jumped over the lazy dog");


///The Sort Method Way

function findLongestWord(str) {
  // Step 1. Split the string into an array of strings
  var strSplit = str.split(' ');
  // var strSplit = "The quick brown fox jumped over the lazy dog".split(' ');
  // var strSplit = ["The", "quick", "brown", "fox", "jumped", "over", "the", "lazy", "dog"];
  
  // Step 2. Sort the elements in the array
  var longestWord = strSplit.sort(function(a, b) { 
    return b.length - a.length;
  });
  /* Sorting process
    a           b            b.length     a.length     var longestWord
  "The"      "quick"            5            3         ["quick", "The"]
  "quick"    "brown"            5            5         ["quick", "brown", "The"]  
  "brown"    "fox"              3            5         ["quick", "brown", "The", "fox"]
  "fox"      "jumped"           6            3         ["jumped", quick", "brown", "The", "fox"]
  "jumped"   "over"             4            6         ["jumped", quick", "brown", "over", "The", "fox"]
  "over"     "the"              3            4         ["jumped", quick", "brown", "over", "The", "fox", "the"]
  "the"      "lazy"             4            3         ["jumped", quick", "brown", "over", "lazy", "The", "fox", "the"]
  "lazy"     "dog"              3            4         ["jumped", quick", "brown", "over", "lazy", "The", "fox", "the", "dog"]
  */
  
  // Step 3. Return the length of the first element of the array
  return longestWord[0].length; // var longestWord = ["jumped", "quick", "brown", "over", "lazy", "The", "fox", "the", "dog"];
                                // longestWord[0]="jumped" => jumped".length => 6
}

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

//WithoutComments 

function findLongestWord(str) {
  var longestWord = str.split(' ').sort(function(a, b) { return b.length - a.length; });
  return longestWord[0].length;
}
findLongestWord("The quick brown fox jumped over the lazy dog");

//Reduce Method

function findLongestWord(str) {
  // Step 1. Split the string into an array of strings
  var strSplit = str.split(' ');
  // var strSplit = "The quick brown fox jumped over the lazy dog".split(' ');
  // var strSplit = ["The", "quick", "brown", "fox", "jumped", "over", "the", "lazy", "dog"];

  // Step 2. Use the reduce method
  var longestWord = strSplit.reduce(function(longest, currentWord) {
    if(currentWord.length > longest.length)
       return currentWord;
    else
       return longest;
  }, "");
  
  /* Reduce process
  currentWord      longest       currentWord.length     longest.length    if(currentWord.length > longest.length)?   var longestWord
  "The"             ""                  3                     0                              yes                          "The"
  "quick"           "The"               5                     3                              yes                         "quick"
  "brown"           "quick"             5                     5                              no                          "quick"
  "fox"             "quick"             3                     5                              no                          "quick"
  "jumped"          "quick"             6                     5                              yes                         "jumped"
  "over"            "jumped"            4                     6                              no                          "jumped"
  "the"             "jumped"            3                     6                              no                          "jumped"
  "lazy"            "jumped"            4                     6                              no                          "jumped"
  "dog"             "jumped"            3                     6                              no                          "jumped"
  */
  
  // Step 3. Return the length of the longestWord
  return longestWord.length; // var longestWord = "jumped" 
                             // longestWord.length => "jumped".length => 6
}

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

//WithoutComments
function findLongestWord(str) {
  var longestWord = str.split(' ').reduce(function(longest, currentWord) {
    return currentWord.length > longest.length ? currentWord : longest;
  }, "");
  return longestWord.length;
}
findLongestWord("The quick brown fox jumped over the lazy dog");

//MathMax
function findLongestWordLength(s) {
  return s.split(' ')
    .reduce(function(x, y) {
      return +Math.max(x, y.length)
    },0);
}
findLongestWordLength("The quick brown fox jumpeed over the lazy dog");

//Advance Solution

function findLongestWordLength(str) {

  //split the string into individual words 
  //(important!!, you'll see why later)
  str = str.split(" ");

  //str only has 1 element left that is the longest element, 
  //return the length of that element
  if(str.length == 1){
    return str[0].length;
  }

  //if the first element's length is greater than the second element's (or equal) 
  //remove the second element and recursively call the function)
  if(str[0].length >= str[1].length){
    str.splice(1,1);
    return findLongestWordLength(str.join(" "));
  }

  //if the second element's length is greater than the first element's start 
  //call the function past the first element 
  if(str[0].length <= str[1].length){
    // from the first element to the last element inclusive.
    return findLongestWordLength(str.slice(1,str.length).join(" "));
  }
}
findLongestWordLength("The quick brown fox jumpeed over the lazy dog");