PHP study notes_PHP tutorial

Here we collect some knowledge points encountered in the process of learning PHP.
1 ,reset() rewinds the internal pointer of array to the first element and returns the value of the first array element. 2.PHP is not licensed under the GPL, but its own license allows redistribution of code and/or binaries. 3. Internally, PHP stores the data and type owned by the variable separately. Types are stored in separate tables. Whenever an expression containing a different type occurs, PHP automatically determines what the programmer wants to do, changes the type in the table, and automatically evaluates the expression. 4,=== operator (yes, there are three equal signs). The difference is that this operator compares both the value and the type of the data. 5. User-defined functions are very expensive in terms of using CPU and memory resources. This is mainly because PHP is interpreted and loosely typed.
6, Do not automatically wrap lines...>/textarea>Automatically wrap lines...>/textarea>
7, We often encounter script programs that fail to find multi-threaded library files. At this time, you should check whether MIT-pthreads has been installed in the system. If not, then install the software. Linux users must install LINUXThreads. These library files are critical to MySQL's multi-threaded running mode (that is, running multiple versions of itself).
8,The environment variables are not hashed into the $HTTP_ENV_VARS[]. To access;environment variables, you can use getenv() instead.
9,Applet is a small program written in Java. It can be embedded in HTML just like images. :
DHTML is similar to a scripting language. It is also interpreted by the browser to generate HTML code representing the content of the page. The only difference is that DHTML can have some additional features, such as making the page functional and using absolute coordinates to accurately position text and pictures.
10. When W3C (The World Wide Web Consortium) promulgated the HTML4 standard in 1997, it also announced the first standard for style sheets, CSS1
The definition of CSS is composed of three parts: selector (selector) ), properties and values ​​of properties. The basic format is as follows: selector {property: value}

11. Here are several common events (more events are used, please check the relevant information): onClick: mouse click event. (Refers to when the mouse is pressed and then released.) onDblClick: Mouse double-click event. (Refers to the mouse being pressed quickly, released, and pressed again.) onMouseDown: Mouse press event. (Occurs when the mouse is pressed.) onMouseUp: Mouse release event. (Refers to the mouse from the pressed state to the bounced state.) onMouseMove: Mouse move event. (Refers to moving the mouse on a specific element.) onMouseOver: Mouse over event. (It means that it occurs when the pointer moves from the outside world to the element.) onMouseOut: mouse leaves event. (Occurs when the mouse leaves a specific element.) onLoad: loading event. (Occurs when the image or page ends loading.) onUnload: Unload event. (Occurs when a visitor leaves the page.) onScroll: Scroll bar scroll event. (Generated when the visitor uses the scroll to move up or down.)
12,L Is it a leap year? If it is a leap year, it is 1, otherwise it is 0 if ($i == 2) { if (date("L") == true) { $TotalDay = 29; } else { $TotalDay = 28; } }
13,: tells thebrowser to load http://www.htmlhelp.com/ 10 seconds after the current documenthas finished loading.
14, PHP installation: CGI and modules
#ScriptAlias ​​/php/ "c:/php/"#AddType application/x-httpd-php .php#Action application/x-httpd-php " c:/php/php.exe"LoadModule php4_module "c:/php/sapi/php4apache2.dll"AddType application/x-httpd-php .php