Talk about PHP syntax (3)_PHP tutorial
Author: Hua Honglang
Text:
As mentioned above ("Talk about PHP Grammar (2)"), it is very convenient to submit form information in PHP. However, what is the life cycle of the variables in the submitted form information? This article comes to Kunming to talk about this issue.
There is no doubt that the parameters of the form will be passed to the next handler. Because, we have had such an example. But will it continue to be passed to the next handler?
The answer is no! The parameters submitted by a Form form are only passed to the first handler, and they will not take effect in the next handler. Let’s take a look at the following example:
File: table.html
File: deal-1.php
echo "";
echo "You like $start, right?
" ;
echo "Try to see if it will be passed on again";
echo "" ;
?>
File: deal-2.php
echo "";
echo "Can you say $start? ? ";
echo "";
?>
From the above example, we can see: the result of deal-1.php processing is (assuming we The input in table.html is "Jacky Cheung"):
You like Jacky Cheung, right?
Try whether it will be passed on again
It means that the form submitted the variable $start to deal-1.php, and in the display result of deal-1.php, if we click the link "Try Will it be passed on again?" After that, the processing result of deal-2.ph Kunp is:
Do you agree?
Obviously, $start is not passed to deal-2.php. But, how do we extend the life cycle of $start? In fact, this is very simple, just use the parameter passing method. For example, we can change deal-1.php to this:
echo "";
echo "You like $start, right? ?
";
echo "Try if it will be passed on again";
echo " ";
?>
If you separate the program, you will find that you only need to add "?start=$start" after deal-1.php, and What this does is parameter passing. For example: http://zhuagk12.oso.kuncom.cn/cartoon.php?no=1 What follows is the parameter, no is the parameter name, and its value is 1. In this way, the variable $no will be generated in the cartoon.php program, with a value of 1. If more than two parameters are passed, separate them with &. For example: http://zhuagk12.oso.com.cn/cartoon.php?no=2&debug=1
In order to extend the life cycle of parameters, we can also use Cookie or Session to achieve this. I won’t go into details here. You will see their usage in future articles.
--(to be continued)--

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

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PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

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