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

Posted by David Hoffman
David Hoffman
12,707 Points

Conditional statements help needed.

Ok so here is my task: There are three list items in the index.html file. We want to be able to enter a 0, 1 or 2 in the text field to embolden the list item with the corresponding index. Can you figure out what condition to put into the if statement to make this code work? I guess that I am just having a complete mind bend. Any help would be much appreciated.

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 (law.indexOf) {

           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>

2 Answers

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

You need a complete conditional expression.

And don't over-think it. All you need there is to test if the current loop index is the same as the value that was entered. And the provided code has already converted the entry into a numeric value for you.

David Hoffman
David Hoffman
12,707 Points

That is exactly what I thought when I first tried the challenge. This is what I first entered; if (index === laws[i]) { It tells me that this is incorrect.

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

You don't want to compare the numeric value of the input to the element at index "i", you just want to compare it with the index itself.

David Hoffman
David Hoffman
12,707 Points
David Hoffman
David Hoffman
12,707 Points

Thank you very much. I was overthinking that way to much.