Question

I have a text box(txt_to) which has values seperated by ; How can I split the values, and even if there is only one value the code should not through error.

I tried to split it with the following code but got an error

string[] recipients = Request.Form["txt_to"].Split(';');
Object reference not set to an instance of an object.

The values in the text box are either a email like ([e-mail]) or just a plain text like (Ios Group). the values in the text box are like [e-mail]; Ios Group. How to split the value and how to check whether it is email id or just a plain text

if(email id)
{
Do this
}
else if (Plain text)
{
Do this
}

Answer 1

RFC 2822 states that you can validate an e-mail with the following regular expression:

[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?

So you can do:

if (Regex.IsMatch(input, **REGEX STRING HERE**))
{
    // E-mail
}
else
{
    // Not an e-mail
}