xxxxxxxxxx<html lang="en"><head><meta charset="utf-8"><title>jQuery Set Element's Attribute Value</title><script src="https://code.jquery.com/jquery-3.5.1.min.js"></script><script>$(document).ready(function(){ $("button").click(function(){ $('input[type="checkbox"]').attr("checked", "checked"); });});</script></head><body> <p><label><input type="checkbox"></label> I agree with terms and conditions.</p> <button type="button">Check</button></body></html>