acbrent25
9/4/2017 - 4:30 PM

Palindrome Detector: A palindrom is a sentence that reads the same backwards and forwards: "Was it a car or a cat I saw?" Reverse each word

Palindrome Detector: A palindrom is a sentence that reads the same backwards and forwards: "Was it a car or a cat I saw?"

Reverse each word in a sentence and display it on the screen in the same order. For example, the sentence This is an example would become siht si na elpmaxe. If the word is a palindrome, have it display in red.

Notes:

Remove periods. Add the result to the page in the div with the id "Result". Bonus:

Remove all "special characters" (commas, periods, etc). Do not use the reverse() method. Here are some test phrases to put in your JavaScript:

"Otto bought a racecar he cannot afford." "Otto lost the deed to his house." "Otto needs Xanax."

index.html
content_copyfile_download
<!DOCTYPE html>

<html lang="en-us">

  <head>

    <meta charset="UTF-8">
    <title>Reverse in Place w/Palindrome Detector</title>

  </head>

  <body>

    <h1>Reverse in Place w/Palindrome Detector</h1>
    <h3>Your result should appear in the div below:</h3>

    <div id="result"></div>

    <!-- Script -->
    <script type="text/javascript" src="app.js"></script>

  </body>

</html>
app.js
content_copyfile_download
var sentence1 = "Otto bought a racecar he cannot afford.";
var sentence2 = "Otto lost the deed to his house.";
var sentence3 = "Otto needs Xanax.";


// Example for special characters bonus.
var sentence4 = "On the way to get Xanax, Otto found a Kayak. He couldn't believe his luck!";


function palindromeDetector(s) {

  // To hold the array of reversed words.
  var reversedArray = [];

  // To hold split the sentence into an array of words.
  var words = s.split(" ");

  // To hold words to be shown on page.
  var showOnPage = [];


  // Loops over each word
  for (var i = 0; i < words.length; i++) {

    // Removing all non-letters with RegEx for bonus.
    words[i] = words[i].replace(/[^a-zA-Z]+/g, "");

    // Or
    // Basic, just replacing the period.
    // words[i] = words[i].replace(".", "");
    // Splits current word into an array of letters.
    var letters = words[i].split("");

    // Using .reverse method
    // Reverses letter array and then joins them into a string.
    // reversedAndJoined = letters.reverse().join("");
    // Or
    // Without using .reverse
    // Blank string to hold the reversed word.
    var reversedAndJoined = "";

    // Loops BACKWARDS over the letter array.
    for (var l = letters.length - 1; l >= 0; l--) {

      // Adds the letters to the string above.
      reversedAndJoined += letters[l];
    }

    // Adds individual reversed word to the array of reversed words.
    reversedArray.push(reversedAndJoined);
  }

  // Loops over the array of reversed words.
  for (var j = 0; j < reversedArray.length; j++) {

    // Checks to see if a word is longer than one letter and checks the reversed word against the unreversed word.
    // (Using toLowerCase so it will ignore any capital letters).
    if ((reversedArray[j].length > 1) && (reversedArray[j].toLowerCase() === words[j].toLowerCase())) {

      // If its a palindrome, it wraps the word in a span to make it red, then pushes it to the showOnPage array.
      showOnPage.push("<span style='color:red'>" + reversedArray[j] + "</span>");
    }
    else {

      // Not a palindrome, just push the plain word.
      showOnPage.push(reversedArray[j]);
    }
  }

  // Replaces the contents of the "result" div with the merged showOnPage array.
  document.getElementById("result").innerHTML = showOnPage.join(" ");
}