Getting Started with PHP

• The PHP script can be placed anywhere in the document.
• The PHP script begins with <?php and ends with?>:
• PHP files usually contain HTML tags and some php script code.
• PHP comments//#/* */Three kinds
• PHP function is case insensitive, but variables in PHP are case sensitive
• Using. To connect two strings in PHP
• Echo Output string/value, auto match
• Every line of code to; end
• The variables in PHP must start with $, without the command to create the variable, and the variable will be created at the first assignment

Instance

<! DOCTYPE html>

• Variable scope and function usage
• To use global variables, write to the function block: global $a; You can use a outside of the function

Global scope function MyTest () {  //local scope  echo "<p> variable:</p> inside the test function";  echo "Variable x is: $x";//The output variable can be written in the string  echo "<br>";  echo "Variable y is: $x";} MyTest (); echo "<p> variable:</p> outside the test function"; echo "variable x is: $x"; echo "<br>" echo "Variable y is: $x";? >

PHP Static Keywords

Typically, all variables are deleted when the function finishes/executes. However, sometimes I need to not delete a local variable. Achieving this requires a bit of further work.

To do this, use the static keyword when you first declare a variable:

Instance

<?phpfunction myTest () {  static $x =0;  echo $x;  $x + +;} MyTest (); MyTest (); MyTest ();? >

Running an instance

Then, whenever the function is called, the information stored by the variable is the information contained in the last Call of the function.

Note: The variable is still a local variable of the function.

The $_get variable is an array of variable names and values that are sent by the HTTP GET method. [1] The $_get variable is used to collect values from a form method= "GET". Information sent from a form with a GET method is visible to anyone (displayed in the browser's address bar) and has a limit (up to 100 characters) to the amount of messages sent.Example<form action= "welcome.php" method= "Get" > Name: <input type= "text" name= "Name"/> Age: <input type= "text" n Ame= "Age"/> <input type= "Submit"/> </form> when the user clicks the Submit button, the URL is sent like this:/welcome.php?name=peter&age= The PNs "welcome.php" file can now get form data through the $_get variable (note that the name of the form field automatically becomes the ID key in the $_get array): welcome<?php echo $_get["name"]; <br/> are<?php echo $_get["age"];? >years old!

Query on Demand

Getting Started with PHP