Verify the mailbox regular expression, including two level domain name mailbox, mobile phone number regular expression support 170th number segment

[0-9a-z] [a-z0-9\._-] {1,}@[a-z0-9-]{1,}[a-z0-9] (\.[ A-z]{1,}) +

Many of the verification mailboxes that were found on the Internet do not support the verification of mailbox of level two domain name

How to use JS

function checkemail (email) {     if (/^[0-9a-z][a-z0-9\._-]{1,}@[a-z0-9-]{1,}[a-z0-9] (\.[ A-z]{1,}) +$/. Test (email) {        returntrue;     }      return false ;}

How to use C #

classProgram {Static voidMain (string[] args) {Console.WriteLine (Checkemail ("[email protected]")); Console.WriteLine (Checkemail ("[email protected]")); Console.WriteLine (Checkemail ("[email protected]")); }         Public Static BOOLCheckemail (stringemail) {Regex reg=NewRegex (@"[0-9a-z][a-z0-9\._-]{1,}@[a-z0-9-]{1,}[a-z0-9] (\.[ A-z]{1,}) +", regexoptions.ignorecase); if(Reg. IsMatch (email)) {return true; }            return false; }    }

Phone number Same as

1[3,4,5,8,7][0-9]{9}

JS usage

/^1[3,4,5,8,7][0-9]{9}$/

C # Usage

@ "1[3,4,5,8,7][0-9]{9}"

Verify the mailbox regular expression, including the level two domain name mailbox, mobile phone number regular expression support 170th number segment