Need regex for specific requirement

Question

Hello,

 

I need regex for following requirement .

 

1.   Need regex for decimal number in which i can dynamicaly change its scale.  like 12, 123.2, 132.22, 23.2222

2.   Need regex for Url which can have http or https or not have this. but url must www.abc.com.

      it can be    http://www.abc.com

                        https://www.abc.com.au

                or    www.abc.com         

 

Thanks in advance.