PHP Basics Review 2018-06-18

(1) cookie-related

Cookies are often used to identify users. A cookie is a small file that the server leaves on the user's computer. Whenever the same computer requests a page through a browser, it also sends a cookie.

How do I create a cookie?

The Setcookie () function is used to set cookies. Syntax: Setcookie (name, value, expire, path, domain);

Note: When a cookie is sent, the value of the cookie is automatically URL-encoded and automatically decoded upon retrieval (to prevent URL encoding, use Setrawcookie () instead).

How do I retrieve the value of a Cookie?

PHP's $_cookie variable is used to retrieve the value of the COOKIE.

How do I delete cookies?

When you delete a cookie, you should change the expiration date to a past point in time.
Setcookie ("User", "", Time ()-3600);

(2) PHP Sessions

The PHP session variable is used to store information about a user's session or to change settings for a user session. The Session variable holds information that is single-user and can be used by all pages in the application.

Turn on Session:session_start ().

The correct way to store and retrieve session variables is to use PHP $_session variables.

To delete some session data, you can use the unset () or Session_destroy () function.

(3) PHP Filter_var () function

Function: Gets a variable and filters it.

Syntax: Filter_var (variable, filter, options)

example, filtering an email

$field=filter_var ($email,if(Filter_var ($field, filter_validate _email)) {    returnTRUE;} Else {    returnFALSE;}

The second parameter of the function is commonly judged:

Filter_validate_url validates the value as a URL.
Filter_validate_email the value as an e-mail to verify.
Filter_validate_ip the value as an IP address to verify.
Filter_validate_float validates the value with a floating-point number.
Filter_sanitize_email Delete all characters except letters, numbers, and!#$%& ' *+-/=?^_ ' {|} [Email protected] []

PHP Basics Review 2018-06-18