Detailed explanation of COOKIE support in PHP_PHP tutorial

One: Set cookies
Cookies must be set before using cookies.
Function prototype: int setcookie(string name, string value, int expire, string path, string domain, int secure)
Among them, except name, all parameters are optional, and an empty string can be used to indicate that they are not set.
Attribute value: used to specify the value.
Attribute path: used to specify that the cookie is sent to the server Which directory path.
Attribute domain: can limit the sending of cookies on the browser side.
expire parameter: used to specify the validity time of the cookie, which is a standard Unix time stamp.
Can be obtained using the time() or mktime() function, in seconds.
secure parameter: Indicates whether this cookie is transmitted over the network through the encrypted HTTPS protocol.

Two: Settings Things to note when using cookies
Setting cookies on the same page is actually done from back to front. If you want to delete a cookie first and then write a cookie, you must first write Enter the statement, and then write the delete statement. Otherwise, an error will occur.

Three: setcookie example
Simple: setcookie("mycookie","value_of_mycookie");
With Expiration time: setcookie("withExpire","Expire_in_1_hour",time()+3600);
Everything is available: setcookie("FullCookie","Full_cookie_value",time+3600,"/forum","www .123.com",1);

Four: Some characteristics of cookies
Cookies are path-oriented. When the default path attribute is used, the WEB server page will automatically pass the current path Specifying a path for the browser will force the server to use the set path.
Cookies set in one directory page cannot be seen in another directory page.

Five: Receive And processing cookies
PHP's processing of cookies is fully automatic, and the principle of processing FORM variables is the same. Of course, you can also use PHP global variables, the $HTTP_COOKIE_VARS array.
Example: echo $mycookie;
echo $cookie Array[0];
echo count($cookie Array);
echo $HTTP_COOKIE_VARS["mycookie"];

Six: Delete cookies
(1) Call setcookie() with only name parameter;
(2) Set the expiration time to time() or time-1;

Seven: Limitations on using cookies
(1) Must be set before the content of the HTML file is output;
(2) Different browsers handle cookies inconsistently, so you must consider them when using them;
(3) Client restrictions, such as If the user settings prohibit cookies, the cookie cannot be created;

8: A specific example, I hope everyone has a deeper understanding of cookies