Questions.

[IwnfuM]

this syntax is good to check email like this email ?

([a-zA-Z0-9]+)@([a-zA-Z0-9]+)[.]([a-zA-Z0-9]+) .

 

and a questions.

how does i tell the syntax to notice if there is a dot.

what is the meaning of ( this / thing ) .

and what the meaning of () .

 

thanks , Mor.

[ZachMEdwards]

Well to match an email address according to RFC 2822 standard, you have to use this pattern:

'/(?:[a-z0-9!#$%&\'*+\/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&\'*+\/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(??:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(??:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])/i'

 

Which is suggested not to use.

 

Here's a simplified version, and probably the best to use:

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

 

To answer your questions:

To show a dot, use \.  It will escape the . (dot) character, so it matches "."

The forward slash "/" is used to show the start or end of the regular expression.

The parentheses are used as capturing groups. They capture what's inside them, for example:

$str = "My name is Susan. My name is Robert.";
preg_match_all('/My name is ([^.]+)\./', $str, $matches);
print_r($matches);

Run that script!

[JasonLewis]

You can validate emails with filter_var if it's available to you.