How to add inline javascript using createElement

How to add inline javascript using createElement

Here  are the 2 examples of codes.

Code 1:

<script>
var scriptNode          = document.createElement ("script");
scriptNode.textContent  = "alert('aaa');";
document.head.appendChild (scriptNode);
</script>

Code 2:

<script>
var scriptNode=document.createElement("script");
scriptNode.textContent= "!function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function(){n.callMethod?n.callMethod.apply(n,arguments):n.queue.push(arguments)};if(!f._fbq)f._fbq=n;n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window,document,'script','https://connect.facebook.net/en_US/fbevents.js');fbq('init',  'mynumber' );fbq('track', 'PageView', {customer_groups: 'Visitatore',default_customer_group: ''});";
document.head.appendChild (scriptNode);
</script>