PHP----Learning Notes (i)

What is PHP:

PHP refers to PHP: Hypertext Preprocessor (Translator note: Php:hypertext preprocessor, recursive naming)

PHP is a server-side scripting language, similar to ASP

PHP scripts are executed on the server

PHP supports many databases

PHP is an open source software (open source Software,oss)

What is a PHP file:

PHP files can contain text, HTML tags, and scripts

PHP file returns pure HTML to the browser

The file suffix of the php file is ". php", ". PhP3", ". phtml"

PHP script block starts with <?php and ends with?>

Two basic instructions for entering text via PHP: Echo and print

All variables in PHP start with the $ symbol

Variable naming rules:

Variable names must begin with a letter or underscore "_"

Variable names can contain only alphanumeric characters and underscores

Variable names cannot contain spaces. If the variable name consists of multiple words, you should use an underscore to split it, or start with an uppercase letter.

The collocated operator.

Strlen () to calculate the length of a string

Strpos () to retrieve a string or a character within a string

To create a PHP function:

1, all functions use the keyword "function ()" to start

2. Named function-the name of the function should indicate its function. The function name begins with a letter or underscore.

3. Add "{"-the section after opening curly braces is the code of the function

4. Inserting function code

5. Add a "}"-the function ends by closing the curly braces.

$_get HTTP GET method

$_pos HTTP Post method