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

Posted by Arnold Nunez
.a{fill-rule:evenodd;}techdegree
Arnold Nunez
Front End Web Development Techdegree Student 9,494 Points

How do I approach this if loop? I have included the index and law variables as conditions and it comes up wrong.

I have included the index and law variables as conditions and it comes up wrong. I have tried variations of "if (law == index)" and 'if (e.target == index)" and more.

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 === index) {

           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

Samuel Zhen
Samuel Zhen
33,571 Points

Then you can replace it with 

if (i === index) {
  law.style.fontWeight = 'bold';
} else {
  law.style.fontWeight = 'normal';
}
Samuel Zhen
Samuel Zhen
33,571 Points
Samuel Zhen
Samuel Zhen
33,571 Points

I assume you want to give your chosen law a bold font weight after you click the button? Try this

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

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

    // Reset all text back to normal weight
    for(let i = 0; i < laws.length; i++) {
        laws[i].style.fontWeight = 'normal';
    }

    // Bold chosen text
    laws[index - 1].style.fontWeight = 'bold';
});

When you do law === index, you're comparing a li element with input text value, that's why your code didn't work.

Arnold Nunez
.a{fill-rule:evenodd;}techdegree
Arnold Nunez
Front End Web Development Techdegree Student 9,494 Points

This seems to make sense but the challenge of this task is to replace just the false condition to make the if loop work. The challenge is that the list item index that matches the input field, should have its font weight changed. Thank you though.