This Drupal 8 code snippet provided is a hook implementation that alters a specific form in a custom module named myModule.

Here's a breakdown of what the code does:

1. Function Hook: The function `myModule_form_alter()` is designed to modify forms and is part of the Drupal form API. It's invoked for every form on the site, allowing custom alterations based on the form ID.

2. Target Form: The form alteration targets the form with the ID `commerce_billing_schedule_edit_form`.

This Drupal 7 CodeLet creates a link to the SCORM or HTML 5 course from the uploaded zip file. This associates an SCORM or HTML course to a node in Drupal.

This CodeLet alter the 'uc_paypal_wps_email' variable when PayPal payment is enabled with Ubercart & sets to node author's PayPal account email address. This requires creating a field on user's account with name 'PayPal Email' (field_paypal_email).

This CodeLet set title and body field values using Ajax. 
Place this CodeLet to your custom module file(.module) or Create a Custom module for Drupal 8 as per documentation https://www.drupal.org/docs/8/creating-custom-modules.

First of all add a field(field_link) to your content type. after that add an ajax to that field as per CodeLet.
Ajax example to replace multiple fields on ajaxCallback.
You set multiple fields value on ajax trigger in Drupal 8.

This CodeLet integrates Aframe libray & displays images using Aframe. With a VR enabled device, you can then view it in VR. It first displays a wall of images. When user clicks on one of them, on a new page, it displays the image using aframe library.

Use this CodeLet to remove "N/A" option from radio button list options. 
Place this CodeLet to your custom module file(.module) or Create a Custom module for Drupal 8 as per documentation https://www.drupal.org/docs/8/creating-custom-modules 
 

This CodeLet will read data from an external API, parse the JSON response & build a node of specific type. It imports taxonomies & images as well. The fascinating thing about this CodeLet is, it can import data to multi - value node fields, including multi widget fields & different field types.

This CodeLet demonstrates the use of hook_form_alter & hook_menu.
Using hook_form_alter, a text field is added to site information page. Once a API key is saved, the button has value 'Update configuration'
Using JSON menu, one can pull a node of type page, as JSON string.

This CodeLet let you programmatically create a form page and render same form on a block. Create custom module and follow CodeLet instruction to create a form and block programmatically.

This CodeLet Sends an email after a node of specific content type is created. The CodeLet uses Drupal8 API which sends and email upon node creation. This CodeLet implement hook_entity_insert & hook_mail.
Place this CodeLet on your MYMODULE.module file.