CSS Initial Learning

Code implementation: PHP

Naming conventions:

<?php

Single-line Comment

/*

Multi-line comments

*/

There are actually # and; comments (both Single-line comments), But more for configuration files

?>

Basic syntax for PHP

PHP program writing and and running

Declarations of constants and variables

1+2x=3;

All are constants; x is a variable

Equivalent

$x =1

1+2* $x = 3;

C C + + Java variable description int (model) x=1; String (string Type) x= "abc",

and PHP declaration directly with the $ sign + variable name, such as $x=1;

PHP declaration with $ sign

Constant declaration in PHP $abc= "php" (constant By default all letters are Capitalized)

Declare variable $abc= "zhang san" in PHP (variable default all letters Lowercase)

The variable must be used before the $, declaration and use must have this symbol

Cannot start with a number

You cannot use a system keyword as a variable name with PHP

note: PHP variables are case-sensitive (only variables and constants are case-sensitive, others are Not)

Variable names must be meaningful, you can use English words, you can also use Hanyu Pinyin. AAA BBB CCC

Naming styles for $AAABBBCCC variables

Define ("server", "servers")

<! DOCTYPE html>

<meta http-equiv= "content-type" content= "text/html"; charset= "utf-8" >

<title></title>

<body>

<?php

$sysos =$_server["server_software"]; Gets the string for the server identity

$sysversion =php_version; //get PHP Server version

The following two code connects to MySQL database and obtains MySQL database version information

Mysql_connect ("localhost", "root", "123456");

$mysqlinfo =mysql_get_server_info ();

Get information about the GD library in the server

If (function_exists ("gd_info")) {

$gd =gd_info ();

$gdinfo = $gd ["gd Version"];

}else{

$gdinfo = "unknown";

}

See if FreeType fonts are supported from the GD library

$freetype = $gd ["freetype support"]? " Support ":" does not support ";

Get the remote file from the PHP configuration file

$allowurl =ini_get ("allow_url_fopen")? " Support ":" does not support ";

Get maximum upload limit from PHP configuration file

$max _upload=ini_get ("file_uploads") ini_get ("upload_max_filesize"): "Disabled";

To get the maximum execution time of a script from a PHP configuration file

$max _ex_time=ini_get ("max_execution_time"). " Seconds ";

The following two get server time, mainland China is using the time of the East eight, set the timezone to write tc/gmt-8

Date_default_timezone_get ("etc/gmt-8");

$systemtime =date ("y-m-d h:i:s", time ());

/* *************************************************************   */

/* output The server information obtained above to the client browser as an HTML table */

/* *************************************************************   */

echo "<table align=center cellspacing=0 cellpadding=0>";

echo "<caption>

echo "<tr><td>web server: </td> <td> $sysos </td> </tr>";

echo "<tr><td>php version: </td> <td> $sysversion </td> </tr>";

echo "<tr><td>mysql version </td> <td> $mysqlinfo </td> </tr>";

echo "<tr><td>gd version </td> <td> $gdinfo </td> </tr>";

echo "<tr><td>freetype </td> <td> $freetype </td> </tr>";

echo "<tr><td> remote file get:</td> <td> $allowurl </td> </tr>";

echo "<tr><td> max upload limit: </td> <td> $max _upload </td> </tr>";

echo "<tr><td> max execution time: </td> <td> $max _ex_time</td> </tr>";

echo "<tr><td> server time: </td> <td> $systemtime </td> </tr>";

Echo "</table>";

Echo "the Current operating system is:". Php_os. " <br/>\n\n ";

echo "the Current file name is:". __file__. " <br/> ";

echo "the Current file name is:". __line__. " <br/> ";

For ($i =1; $i <10; $i + +) {

For ($j =1; $j < $i +1; $j + +) {

echo $j. ' x '. $i. ' = '. $i * $j. " \ t ";

}

Echo ' <br/> ';

}

?>

</body>

Expressions for operators

Declaring methods in PHP function get

This article from "12145719" blog, declined reprint!

CSS Initial Learning