Mobile Number (Cellphone Number) Validation using Data Annotations and RegularExpressions (Regex) in ASP.Net MVC

Here Mudassar Ahmed Khan has explained with an example, how to perform Mobile Number (Cellphone Number) TextBox validation i.e. exact Ten Numbers (Digits) validations using Data Annotations and RegularExpressions (Regex) on Client Side in ASP.Net MVC Razor. A Mobile Phone Number (Cellphone Number) is a numeric value with exact ten (10) digits and such validation can be achieved using the RegularExpression Data Annotation attribute in ASP.Net MVC Razor.