Final answer:
To change the font size of an h1 tag to 35px on click, you need to add an event listener in JavaScript that modifies the CSS font-size property when the h1 tag is clicked.
Step-by-step explanation:
To write and register an event handler that changes the font size of the h1 tag to 35px on click, you need to use a combination of HTML, CSS, and JavaScript. First set up your HTML structure with an h1 tag. Next, include JavaScript to add the event handler to the h1 element. Here is a simple example:
HTML
:
<h1 id="header">Click me!</h1>
JavaScript
:
document.getElementById('header').addEventListener('click', function() {
this.style.fontSize = '35px';
});
The JavaScript code grabs the element with the ID 'header' and adds a click event listener that changes its font size to 35px when clicked.