Implementation of js and php email address verification

There are many ways to verify the email address. On the Browser Side, js mailbox verification can be detected through regular expressions.

For example:
Copy codeThe Code is as follows:
Function isEmail (email ){
Return/^ ([a-z] | \ d | [! # \ $ % & '\ * \ + \-\/= \? \ ^ _ '{\|}~] | [\ U00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) + (\. ([a-z] | \ d | [! # \ $ % & '\ * \ + \-\/= \? \ ^ _ '{\|}~] | [\ U00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) +) * | (\ x22) (\ x20 | \ x09) * (\ x0d \ x0a ))? (\ X20 | \ x09) + )? ([\ X01-\ x08 \ x0b \ x0c \ x0e-\ x1f \ x7f] | \ x21 | [\ x23-\ x5b] | [\ x5d-\ x7e] | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) | (\ ([\ x01-\ x09 \ x0b \ x0c \ x0d-\ x7f] | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) ))) * (\ x20 | \ x09) * (\ x0d \ x0a ))? (\ X20 | \ x09) + )? (\ X22) @ ([a-z] | \ d | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) | ([a-z] | \ d | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) ([a-z] | \ d |-| \. | _ | ~ | [\ U00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) * ([a-z] | \ d | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) \.) + ([a-z] | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) | ([a-z] | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) ([a-z] | \ d |-| \. | _ | ~ | [\ U00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) * ([a-z] | [\ u00A0-\ uD7FF \ uF900-\ uFDCF \ uFDF0-\ uFFEF]) $/I. test (email );
}

The call is simple:

Copy codeThe Code is as follows:
If (isEmail ('youremail @ yourdomain.com ') {console. log ('this is email is valid ');}

For server-side verification. Php is the simplest:

Copy codeThe Code is as follows:
/*
* Email Address validity Verification
*/

Function isEmail ($ mail_address ){
Return filter_var ($ mail_address, FILTER_VALIDATE_EMAIL );
}

But this can also be complicated.

Like this one. He established a complete email address verification website system. It is estimated that few people do this.

To be honest, I have to admire it.