Use the jQuery attr() method
You can use the jQuery attr() method to add attributes to an HTML element.
In the following example when you click on the "Select Checkbox" button it will add the checked attribute to the checkbox dynamically using jQuery.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery Adding Attribute to HTML Element</title>
<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script>
$(document).ready(function(){
$(".add-attr").click(function(){
$('input[type="checkbox"]').attr("checked", "checked");
});
});
</script>
</head>
<body>
<button type="button" class="add-attr">Select Checkbox</button>
<input type="checkbox">
</body>
</html>
