To set the style of the font, use the fontStyle property. You can try to run the following code to set the style of the font to normal, italic or oblique with JavaScript −
Example
<!DOCTYPE html>
<html>
<body>
<h1>Heading 1</h1>
<p id="myID">
This is Demo Text. This is Demo Text. This is Demo Text. This is Demo Text.
This is Demo Text. This is Demo Text. This is Demo Text. This is Demo Text.
</p>
<button type="button" onclick="display()">Set Font Family and Style</button>
<script>
function display() {
document.getElementById("myID").style.fontFamily = "verdana,sans-serif";
document.getElementById("myID").style.fontStyle = "italic";
}
</script>
</body>
</html>