Why does my LinkedIn inbox always show one unread message ?

Even if I have read all of my Linkedin messages , it still shows one unread message. Strange but true.
I am not sure what is the problem but i can tell how i fixed that.

1. Click on any message that you have already read.
   
2. Mark it as UNREAD
   
3. Click on another message that you have already read.
   
4. Mark it as UNREAD
   

See , if you notice any change in unread messages indicator ?

For me it changed correctly and then I read both messages one by one and it made my all messages as Read.

Have great time using Linkedin :)

Websites for learning Regular expressions

Regular expressions are like swiss knife which can do lot of work in small amount of code.

However knowing them deeply is very important to write code which is optimal.

I found below good websites for them while using and learning about them.

A very good website to have visual debugging for Regular expressions
https://www.debuggex.com/

Website to create and test regular expressions
http://regexr.com/
https://regex101.com/

A good website for Regular expressions tutorials
http://www.rexegg.com/