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Summer precipitation Web Learning -- PHP Foundation

2022-07-16 05:48:00 【Wang Zui Zui】

web Learning process framework

Conceptual understanding

Data flow ： After collecting data from the front end , Send to middleware , Turn the request message into a series of code that the machine can execute directly , Then give it to the back-end language processor , Take data from the database .

PHP Basics

PHP survey

PHP advantage
Doesn't matter , Every language is basically the same

PHP Application fields of
——（1） Server side script
——（2） Command line Scripter
——（3） Desktop applications

HTML Embedded scripting language
PHP Scripts can contain text 、HTML Code and PHP Code
Similar to the feeling of mixing , It can be said that the front-end code is unloaded directly php In the process of

PHP Script workflow

WEB browser
Web browser , The most commonly used client program , The main function is reality HTML Web content , Used to display the final rendered results

HTML brief introduction

PHP Workflow
Client to web The server makes a page request , If the requested resource is a static resource （ No need for dynamic generation , Original resources ）, Such as 1.txt, be web The server directly returns the static page to the client （response）, If you need to request a dynamic resource , Such as 1.php, You need to go through PHP Preprocessor for processing , Interact with the database server , After generating a static page , Then return to our client . So all the results we see in the browser are actually All static pages （html）

PHP Server build

PHPstudy Integrated environment
phpStudy It's a PHP The program integrated debugging environment package . The package integrates the latest Apache+PHP+MySQL+phpMyAdmin+ZendOptimizer, One-time installation , Without any configuration , It is very convenient 、 Easy to use PHP Debug environment .
One button start
Visit local 127.0.0.1

PHP Basic knowledge of

php Basic grammar
1、<?php ?> This means entering PHP Pattern , Everything outside the start and end tags will be PHP The parser ignores .（php Code and HTML Code nested with each other , Pictured ）
2、 Pictured html There are two nested in the file php file , In a html Any number of... Can be embedded in the document PHP Mark ！
3、PHP Languages are executed sequentially
Single-line comments //、#
Multiline comment /* */
Be careful ！ stay php The codes other than the start tag and the end tag are HTML Code , So want to use HTML The annotation style of , for example 
PHP Comments in the code , Will not appear in the browser's source code
PHP The running environment is the server , What we see on the browser side is PHP Engine running PHP Execution result after code
Instruction splitter [;]
PHP Use a semicolon to indicate the end of a sentence

PHP The composition of the program
From a functional point of view , complete PHP The program can be divided into three parts ： Data collection 、 Data processing and data output , among PHP Data acquisition of mainly includes three processes ： Browser side data collection 、 Submission of browser side data and PHP Program data collection .
Variable name
$ The symbol represents a variable , Such as $name
① Case sensitive
② Only in letters | Numbers | Start with an underline , Cannot start with a number

HTML Front end forms ,form action Point to the server to submit url
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>C01 html</title>
</head>
<body>
    <form action="./C01.php" method="get">
         user name ：<input type="text" name="username"/><br/>
         The secret &nbsp;&nbsp;&nbsp; code ：<input type="password"  name="password"/><br/>
         Confirm the password ：<input type="password" name="confirmPassword"/><br/>
    <input type="submit" value=" Submit "/>
    <input type="reset"  value=" Refill "/>
    </form>
</body>
</html>
Try opening with a web page ( Be careful , use ip Address to visit , Not directly open in browser, The former php Only then can we analyze , The latter is the opening method ） And enter the user name and password
use open in browser Words
use ip Address access
PHP The code content will be parsed
obtain C01.php?username=wzz&password=123123&confirmPassword=123123
The parameters written are submitted
So far, the data collection and submission of the browser side have been completed , One less PHP Program data collection
$userName $password $confirmPasswor Are custom variables , It doesn't matter what the name is
$_GET Used to collect data from method="get" Values in the form T The data of , In the heel userName Must follow html The parameter names in the file correspond one by one
Common arrays
【 Common arrays 】
1、$_GET[]
Used to collect data from method="get" Values in the form
2、$_POST[]
Used to collect data from method="post" Values in the form
3、$_COOKIE[]
To accept cookie value
4、$_SESSION[]
Finish right session Data reading and writing
Realization effect , The code is as follows
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title> first php Program </title>
</head>
<body>
    <?php
        //  echo"hello,world";
        //  echo"<br/>";
        //  echo date("Y-m-d H:i:s");
        $username=$_GET["username"];
        $password=$_GET["password"];
        $confirmPassword=$_GET["confirmPassword"];
        if($password=$confirmPassword)
        {
            echo" Registration succeeded ";
            echo "<br/>";
            echo" Your encrypted password is ：";
            echo md5($password);
        }
        else{
            echo" The password you entered is different from the one you confirmed , Please re register ";
        }
     ?>
</body>
</html>

first PHP Program

phpstudy Website —— Click on the management —— Open the root directory
Create a suffix named php Of php file , use VScode open
Exclamatory mark （ In English mode ）+Tab Generate template
Make a simple edit
Web page open

View page source code , Discover original php The content of the line changes , after php After the preprocessor , Turn into such a static page and send it back to me