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JavaScript DOM Scripting By Example Editing and Filtering Names Fix DOM Manipulation Code

Posted by Louis Riddle
.a{fill-rule:evenodd;}techdegree seal-36
Louis Riddle
Front End Web Development Techdegree Graduate 12,982 Points

Im having trouble correcting the test condition

I thought it would be the the value of indexText === to law[i], but I might have a syntax error somewhere or just have faulty logic.

app.js 
const laws = document.getElementsByTagName('li');
const indexText = document.getElementById('boldIndex');
const button = document.getElementById('embolden');

button.addEventListener('click', (e) => {
    const index = parseInt(indexText.value, 10);

    for (let i = 0; i < laws.length; i += 1) {
       let law = laws[i];

       // replace 'false' with a correct test condition on the line below
       if ( index === law  ) {

           law.style.fontWeight = 'bold';
       } else {
           law.style.fontWeight = 'normal';
       }
    }
});
index.html 
<!DOCTYPE html>
<html>
<head>
  <title>Newton's Laws</title>
</head>
<body>
  <h1>Newton's Laws of Motion</h1>
  <ul>
    <li>An object in motion tends to stay in motion, unless acted on by an outside force.</li>
    <li>Acceleration is dependent on the forces acting upon an object and the mass of the object.</li>
    <li>For every action, there is an equal and opposite reaction.</li>
  </ul>
  <input type="text" id="boldIndex">
  <button id="embolden">Embolden</button>
  <script src="app.js"></script>
</body>
</html>

1 Answer

jb30
jb30
44,805 Points
jb30
jb30
44,805 Points

The line const index = parseInt(indexText.value, 10); means that index is an integer (or not a number). const laws = document.getElementsByTagName('li'); and let law = laws[i]; means that law is a list item (or undefined). When you compare index === law, you are comparing an integer to a list item, which will be false. Instead, try comparing two items of the same type.