syntax.txt

Variables
	$ = must be in used before variable at declaration and referencing
	global = keyword used before a global varaible to access it a function

Arrays
	Declaration : $cars = array("BMW","Opel")
		array() = function used for creating arrays
		count() = return length of array

		//Array Sorting

    sort() - sort arrays in ascending order
    rsort() - sort arrays in descending order
    asort() - sort associative arrays in ascending order, according to the value
    ksort() - sort associative arrays in ascending order, according to the key
    arsort() - sort associative arrays in descending order, according to the value
    krsort() - sort associative arrays in descending order, according to the key

Two HTTP Request Methods: GET and POST

	Two commonly used methods for a request-response between a client and server are: GET and POST.

    GET - Requests data from a specified resource
    POST - Submits data to be processed to a specified resource
    NB: Both of them send data

    PHP Variables used with the above HTTP methods respectively
   	  $_GET["form value name"]: Collects data sent through with the GET method (method = "get" in html)
    	$_POST["form value name"]: Collects data sent through with the POST method (method = "post" in html)
    	$_REQUEST["form value name"]: Collects data sent through with both the POST and GET methods

    	NB: These are actually key-based arrays. They store all the form data sent.

    GET Notes

    	GET requests can be cached
   		GET requests remain in the browser history
   	  GET requests can be bookmarked
    	GET requests should never be used when dealing with sensitive data
    	GET requests have length restrictions
    	GET requests should be used only to retrieve data


DATABASES AND PHP

	mysqli_connect(host,username,password,dbname) : function to open new database connection
		All parameters are optional

	mysqli_connect_errno(connection): Checks if connection is established
		mysqli_connect_error: Error message returned. Can publish this with "echo"

	mysqli_close(connection): Close connection

	mysqli_query(connection,query): Sends a query or command to a MySQL connection.

	mysqli_fetch_array("variable to store results in"): Fetches first row from the record set as an array
											: Each successive call fetches next row

	CREATE TABLE EXAMPLE
			$sql = "CREATE TABLE Persons
				(
					PID INT NOT NULL AUTO_INCREMENT,
					PRIMARY KEY(PID),
					FirstName CHAR(15),
					LastName CHAR(15),
					Age INT
				)";


	SELECT EXAMPLE
		<?php
				$con=mysqli_connect("example.com","peter","abc123","my_db");
				// Check connection
			 	if (mysqli_connect_errno())
  			{
  				echo "Failed to connect to MySQL: " . mysqli_connect_error();
 				}

				$result = mysqli_query($con,"SELECT * FROM Persons");

				while($row = mysqli_fetch_array($result))
 				{
  				echo $row['FirstName'] . " " . $row['LastName'];
 					 echo "<br />";
  			}

				mysqli_close($con);
?>

ADVANCED PHP

	Including files(Other php files)
		include 'filename';File is optionally needed to be there for code to run
			or
		require 'filename'; : File must be there for code to run,else program stops

	WORKING WITH FILES
		FILE FUNCITONS

			$file=fopen("file name","mode");
			fclose($file): close file
			feof($file): Evaluates end-of-file
			fgets(): Reads a file line by line
				NB:  After a call to this function the file pointer moves to the next character.
			fgetc():  Reads a file character by character

			UPLOADING FILES TO A SERVER
				enctype="multipart/form-data" : Required in HTML form creation
					:Used when binary data is needed to be sent over a form