What you need to know before learning PHP, learn PHP knowledge_PHP tutorial

What you need to know before learning PHP, learn PHP knowledge

1.Static website and dynamic website

A) Static website:

Websites that do not support data interaction (suffix: .html .htm)

B) Dynamic website:

A website that supports data interaction. Dynamic websites can contain static web pages

i.Technology for implementing dynamic websites

1.Asp .asp

2.php .php

3. .net .aspx

4.Java .jsp

2.Client and server side

A)Client: the computer used by the viewer

B)Server side: the machine that stores website code

C)The client sends a request to the server, (HTTP request), and the server will send the static resource (html, code, pictures, js, CSS) are sent to the client (HTTP response), the client parses the returned code through the browser, forming the page we see.

3.Port and port number

A)The port is the entrance for service operation, similar to the door of a building

B)Port number: The house number of the door. The range is 0~65535

C) How to check whether the port number is being used.

Win R and enter cmd to enter the command line

Enter netstat -ano

D) Port 80 is generally reserved for WEB servers, and port 21 is reserved for FTP is used, and 25 port is reserved for the mail server.

4.BS and CS architecture

A)BSArchitecture

B：brower Browser

S：sever server

Access the server via browser

B)CSArchitecture

C：client Client

S：sever Server

Access the server through a client software

Example: qq, stock trading software

5.Front desk and backstage

A) Front desk: the interface seen by the browser

B)Backend: The interface operated by the administrator. The backend is used to operate the data in the frontend

6.Site, virtual directory, virtual host

A)Site: Folder to store website content

B)Virtual directory: Folder with permissions

C)Virtual host: Folder with permissions Domain name Port

7. Change virtual directory

Because the operation of PHP requires the support of apache, the directory of php needs to be Inform apache to configure the virtualization of php in the large configuration file of apache Table of Contents

Open the configuration file of apache and search for documentroot (the configuration file is not case-sensitive)

Enter http://localhost/text.php(modified virtual directory) in the browser address bar and found that it cannot Reason for opening the specified page: No access permission is set for the changed directory

Solution: In the apache configuration file, set the permissions of the specified folder to allow from all

Change method:

1. Find http.conf under wampwerverbinapacheapache2.4.9conf, open and enter vhosts Search and find the location of the picture below, remove the previous #

2. Find httpd-vhosts.conf under wampserver/bin/apache/apache2.4.9/conf/extra, open it and add the following code at the end of the text

DocumentRoot "D:/wamp/www/web1/"

DirectoryIndex wo.php

ServerName www.sina.com

3. Modify the file C:/WINDOWS/system32/drivers/etc/host, open it with Notepad, and add the following content:

127.0.0.1 www.sina.com

Note: D:/wamp/www/web1/ is the root directory of the website project

7. Change homepage

Look for directoryindex in the configuration file of apache. This command is to set the homepage of the website.

9.Change the listening port

Listen

Browser request format: http://URL[:Port number]/phpPage

If it is the port number 80, then the port number can be omitted.

10.DNSAnalysis

A)DNS: Domain name resolution system. Enter the domain name in the browser and first go to the nearest DNS server to resolve the IP address corresponding to the domain name (the nearest DNS The parsing server is the local machine), and then access the server through the IP address.

The local DNS resolution database is in "C:WindowsSystem32driversetchosts"

11. Features of PHP syntax

PHP keywords are not case-sensitive, variable names are case-sensitive