Below is a list of websites that may help with development.
Regular Expression Explanation
An explanation of a Regular Expression
a regular expression tool
Also add this online regular expression validator (for .NET). If it’s meant to work on the back-end (C#), this website is more accurate and it gives more information.
A scratch pad to test and prototype Angular
Need MSDN licence to activate
If you don’t have an account, log into https://my.visualstudio.com/benefits then activate the pluralsite option which then gets you to create an account on that site, then you can access the courses.