What is the difference between GET and POST methods

What is the difference between GET and POST methods? This article will give you a detailed introduction to the GET and POST methods so that you can understand the difference between the GET and POST methods. I hope it will be helpful to you.

#Web browsers usually use one of the two methods of HTTP (Hypertext Transfer Protocol) (GET method and POST method) to communicate with the server. These two methods pass information in different ways to send data to the server. Let's take a closer look at the GET method and POST method.

GET method

In the GET method, the data is sent as parameters of the URL, which are usually names and A string of value pairs. Typically, a URL with GET data will look like this:

http://www.php.cn/action.php?name = john&age = 24

In the URL name and age are both GET parameters, john and 24 are the values ​​of these parameters; multiple "parameters=value" can be embedded in a URL by concatenating it with the ampersand symbol. One can only send simple text data via GET method.

Advantages and Disadvantages of Using the GET Method

1. Since the data sent by the GET method is displayed in the URL, you can bookmark the page using a specific query string value. .

2. The GET method is not suitable for passing sensitive information such as username and password, because this information is completely visible in the URL query string and may be stored in the memory of the client browser as the accessed page.

3. Since the GET method assigns data to server environment variables, the length of the URL is limited. Therefore, there is a limit on the total data to be sent.

PHP provides the super global variable $_GET to access all information sent through the URL; or use HTML to send information through the information submitted through the HTML form method="get".

POST method

In the POST method, data is sent to the server as a packet in a separate communication with the processing script; sent via the POST method The data is not visible in the URL.

The POST method is suitable for situations where a large amount of information can be transferred. When the server receives a request via a form using POST, it transmits all relevant information entered into the form immediately after making the request to the URL.

Advantages and disadvantages of using the POST method

1. It is more secure than GET because the information entered by the user is never visible in the URL query string or server logs .

2. There is a larger limit on the amount of data that can be transferred. One can use POST to send text data and binary data (upload files).

3. Since the data sent by the POST method is not visible in the URL, you cannot use a specific query to bookmark the page.

PHP will provide another super global variable $_POST to access all information sent through the post method; or use method="post" to send information through an HTML form.

The difference between GET and POST methods

Although, both GET and POST methods send data Go to the server and communicate with the server; but these two methods are different. Let's take a look at the difference between the GET and POST methods.

1. Amount of data sent

In Get, only a limited amount of data can be sent because the data is sent in the URL;

In POST, a large amount of data can be sent because the data is sent in the body of the text.

2. Security

The data sent by the GET method is not protected because the data is exposed in the URL bar, which increases the risk of vulnerabilities and hacker attacks.

The data sent by the POST method is safe because the data is not exposed in the URL bar and a variety of encoding techniques can be used in it, which makes it resilient.

3. Add to bookmarks

The results of GET query can be added to bookmarks because they exist in the form of URL; while the results of POST query cannot be added to bookmarks.

4. Encoding

When using the GET method in the form, only ASCII characters are accepted in the data type.

When the form is submitted, the POST method does not bind the form data type and allows binary and ASCII characters.

5. Variable size

The variable size in the GET method is about 2000 characters. However, the POST method allows a variable size of up to 8 Mb.

6. Cache

The data of the GET method can be cached, but the data of the POST method cannot be cached.

7. Main function

The GET method is mainly used to obtain information. However, the POST method is mainly used to update data.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

The above is the detailed content of What is the difference between GET and POST methods. For more information, please follow other related articles on the PHP Chinese website!