verify email address without sending email

Use regular expressions in JS to verify email address

Use a regular expression to verify the email address and mobile phone number Regular Expression, also known as Regular Expression and Regular Expression (English: Regular Expression, often abbreviated as regex, regexp or RE in code), is a concept of computer science. Regular Expressions use a single string to describe and match a series of strings that conform

Use a regular expression to verify the email address and mobile phone number. Regular Expression, also known as Regular Expression and Regular Expression (English: Regular Expression, often abbreviated as regex, regexp or RE in code), is a concept of computer science. Regular Expressions use a single string to describe and match a series of strings that conform

Verify that the account is validVerification rules: a combination of letters, numbers, and underscores. It must start with a letter and contain 4-16 characters. FunctionCheckuser (STR ){VaRRe=/^ [A-Za-Z] \ W {3, 15} $/;If(Re. Test (STR) {alert ("Correct");}Else{Alert ("Error") ;}} Checkuser ("jiade_cnblogs");//Call Verify mobile phone numberVerification rules: 11-digit number, starting with 1. Funct

Mobile phone number verification (13 opening and 158,159 beginning, total 11 digits) Copy Code code as follows: var re; var Ss=document.getelementbyid (' TextBox3 '). Value; Re=/^ (13[0-9]{9}) | (15[89][0-9]{8}) $/ if (Re.test (ss)) { document.getElementById (' Label3 '). innertext= ""; Assign value to label with InnerText } Else { document.getElementById (' Label3 '). innertext= "Please enter the correct cell phone number!" "; document.getElementById (' ImageB

The main code for verifying the email format is as follows: Public bool isemail (string str_email) { Return System. text. regularexpressions. regEx. ismatch (str_email, @ "^ ([/W-/.] +) @ (/[0-9] {1, 3 }/. [0-9] {1, 3 }/. [0-9] {1, 3 }/.) | ([/W-] + /.) +) ([A-Za-Z] {2, 4} | [0-9] {1, 3}) (/)?] $ "); } The main code for verifying the IP address format is as follows: Public bool ipcheck (string IP) { String

1 // Check whether email has been registered 2 Function Checkexists () 3 { 4 VaR E = Document. getelementbyid ( " Mailaddress " ). Value; 5 If (E ! = "" ) { 6 If ( ! / (\ S) + [@] {1} (\ S) + [.] {1} (\ W) +/ . Test (e )) 7 { 8 Alert ( " Enter an email address in the correct format! "

The code is as follows Copy Code HtmlJsfunction Validate (Form_id,email) {var reg =/^ ([a-za-z0-9_-.]) +@ ([a-za-z0-9_-.]) +. ([a-za-z]{2,4}) $/;var address = Document.forms[form_id].elements[email].value;if (reg.test (address) = = False) {Alert (' Invalid Email