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PHP newbie road 3_PHP tutorial
- WBOYOriginal
- 2016-07-13 17:29:28738browse
b>Learn PHP from a simple program
The online tutorials on the PHP site are already great. This part of the article will make you familiar with PHP. It's impossible for me to miss anything. My purpose is only to allow you to quickly start your PHP programming.
3.1 First Requirements
You must first have a working web server that supports PHP. I assume that all PHP files on your server have the extension .php3.
3.2 Installation of PHP
For the installation configuration of PHP, you can check the special article "Complete PHP Installation Guide" on Taoba website.
3.3 Syntax
From a syntax perspective, PHP language is similar to C language. It can be said that PHP draws on the grammatical features of C language and is improved from C language. We can mix PHP code and HTML code. Not only can we embed PHP scripts into HTML files, we can even embed HTML tags in PHP scripts. Here are a few approaches you can take. You can choose whichever one works best for you and stick with it!
Separate from HTML
Here are the methods you can use:
$#@60;? . . . ?$#@62;
$#@60;?php . . . ?$ #@62;
$#@60;script language="php"$#@62; . . . $#@60;/script$#@62;
$#@60;% . . . %$#@62;
Note: When you use "$#@60;? . . . ?$#@62;" to embed PHP code in an HTML file, it may conflict with XML. At the same time, it can Whether to use this shortened form also depends on the settings of PHP itself. To make your PHP code adaptable to XML and other editors, you can make your PHP code adaptable to XML parsers by adding "php" after the opening question mark. For example: "$#@60;?php. . . ?$#@62;". You can also use script tags like other scripting languages, such as: "$#@60;script language="php"$#@62; . . . $#@60;/script$#@62;".
Statement
Like Perl and C, statements are separated by ";" in PHP. Those separate tags from HTML also indicate the end of a statement.
Comments
PHP supports C, C++ and Unix style comments:
/* C, C++ style multi-line comments*/
// C++ style single-line comments
# Unix Style single-line comments
echo and print
The simplest interaction between PHP and HTML is achieved through print and echo statements. In actual use, the functions of print and echo are almost exactly the same. It can be said that wherever one can be used, the other can also be used. However, there is still a very important difference between the two: in the echo function, multiple strings can be output at the same time, while in the print function, only one string can be output at the same time. At the same time, the echo function does not require parentheses, so echo? is more like a statement than a function. Let's take a look at the following example:
$#@60;?
$a="hello";
$b="world";
echo "a","b" ;
print "a","b";
?$#@62;
After viewing the operation of this code with a browser, you will see the following results:
aba
Parse error: parse error in d:adminmyphphome est.php3 on line 5
This shows that this code cannot be fully explained. The error occurs in the fifth line of the code: "print "a"," b";".
3.4 A simple example
With the knowledge we have learned, you can write the simplest program to output a word that is perhaps the most famous word in the programming world
$#@60;HTML$#@ 62;
$#@60;HEAD$#@62;
$#@60;TITLE$#@62;
$#@60;?
echo "Hello World!";
?$#@62;
$#@60;/TITLE$#@62;
$#@60;/HEAD$#@62;
$#@60;BODY$#@ 62;
$#@60;H1$#@62;
First PHP page
$#@60;/H1$#@62;
$#@60;HR$#@62 ;
$#@60;?
// Single line C++ style comment
/*
printing the message
*/
echo "Hello World!";
# Unix style single line comment
?$#@62;
$#@60;/BODY$#@62;
$#@60;/HTML$#@62;