PHP GET and POST
In this chapter you will learn:
- GET POST Superglobal Array
- Example - Accept value from $_GET and $_REQUEST
- Different between GET and POST
Superglobal Array
To read the data from a form, we can use the following three superglobal variables.
| Superglobal Array | Description |
|---|---|
| $_GET | Contains all the field names and values sent by a form using the get method |
| $_POST | Contains all the field names and values sent by a form using the post method |
| $_REQUEST | Contains the values of both the $_GET and $_POST arrays combined, along with the values of the $_COOKIE superglobal array |
Example
Each of these three superglobal arrays contains the field names from the sent form as array keys, with the field values themselves as array values.
<input type="text " name="emailAddress" value="" />
You could then access the value that the user entered into that form field using either the $_GET or the $_REQUEST superglobal:
$email = $_GET["emailAddress"];
$email = $_REQUEST["emailAddress"];
Different between GET and POST
GET sends its variables in the URL.
It easy to see what was sent with GET.
And user can change what was sent
There is usually a low limit on the number of characters that can be sent in a URL.
If we try to send long variables using GET, we may lose some of them.
POST sends its variables behind the scenes and has a
much higher limit.
It limit is usually several megabytes.
Browsers will not automatically resend
post data if your user clicks the Back button,
you may get a message like
"The data on this page needs to be resent".
This does not happen with GET, browsers will just resend data as needed through URL.
PHP has post_max_size entry in php.ini.
It is usually set to 8M by default, which is 8 megabytes.
Next chapter...
What you will learn in the next chapter: