Today I Learned : PHP

17 nov. 2013 - 3min

I was a tad curious and I took a quick glance at PHP. Not quite knowledge to make an app but fun to discover this language.

First, you need to include PHP in your html code:

<? php
  // include php code there
?>

Never forget to put semicolons (;) as we must do in JS and CSS.

Basics

Variables

<? php
  $str = "I'm learning PHP!";
  $nbr = 9;
  echo $str; // Prompt I'm learning php
  print $nbr; // Prompt 9
?>

Compare values

< > == <= >= !=

Conditionals

If case

if{}elseif{}else{}

Switch case

<? php
switch (2) {
  case 0:
    echo 'The value is 0';
    break;
  case 1:
    echo 'The value is 1';
    break;
  case 2:
    echo 'The value is 2';
    break;
  default:
    echo "The value isn't 0, 1 or 2";
} ?>

Another way to do the switch

switch($i): case 2: ... endswitch;

Arrays

Create an array

$array = array("Egg", "Tomato", "Beans");

Modify

$array = array("Egg", "Tomato", "Beans");
$array[0]="Omlet"; // Egg remplaced by Omlet

Push

$myTable=array("Sausage"); // [Sausage]
array_push($myTable, "Bacon","Egg"); // [Sausage, Bacon, Egg]

Delete

unset($array[0]); // delete first element
unset($array); // delete the array

Foreach

foreach($languages as $lang){
  print "<p>$lang</p>";
}

Sorting the array

$myTable=array();
array_push($myTable, "Bacon","Sausage");
print count($myTable);
sort($myTable); // sortin array
print join(",",$myTable); // returns elements from array into a string with a separator
resort($myTable); // reverse sorting
print join(",",$myTable);

Compute difference between arrays

$A = array("a" => "green", "red", "blue", "red");
$B = array("b" => "green", "yellow", "red");
$result = array_diff($A, $B); // ["blue"]

array_diff($A,$B) returns all elements from $A which are not elements of $B.

String object manipulation

$str="myString"; //create a string
$len=strlen($str); //length of your string
$str=strtoupper($str)//put the string in upper case
$str=strtolower($str) //in lower case
/*substr(string,position first letter,number of letters to display)*/
$str=substr($str,0,3) // "myS"
$pos=strpos($str, 'y'); // get the position of 'y' in $str
if(strpos("alex", "v")===false){
  echo "The letter v doesn't appear in the string";
}
$name="Alex";
$concat="Greetings,".$name."!"; //Concatenation
echo $concat;

Form to send e-mail

<?php
	// Configuration
	$config = array(
				'success' => 'Your message is succesfully send',
				'error_name' => 'You must enter a name',
				'error_firstname' => 'You must enter a firstname',
				'error_mail' => 'E-mail not valid',
				'error_message' => 'You must write a message',
				);
	$_POST['name'] = htmlspecialchars(addslashes($_POST['name']));
	$_POST['firstname'] = htmlspecialchars(addslashes($_POST['firstname']));
	$_POST['email'] = htmlspecialchars(addslashes($_POST['email']));
	$_POST['message'] = htmlspecialchars(addslashes($_POST['message']));
	$d['errors'] = array(); // Errors stack
	// Check name
	if(empty($_POST['name']))
	{
		$d['errors']['name'] = $config['error_name'];
	}
	// Check firstname
	if(empty($_POST['firstname']))
	{
		$d['errors']['firstname'] = $config['error_firstname'];
	}
	// Check e-mail
	if(empty($_POST['email']) || !preg_match('#^[a-z0-9._-]+@[a-z0-9._-]{2,}\.[a-z]{2,4}$#', $_POST['email']))
	{
		$d['errors']['email'] = $config['error_mail'];
	}
	// Check message
	if(empty($_POST['message']))
	{
		$d['errors']['message'] = $config['error_message'];
	}
	// Send e-mail
	if(empty($d['errors'])){
		$d['errors'] = false;
		$receiver = 'contact@domain.com';
		$subject = 'Contact';
		$name = strtoupper($_POST['name']);
		$firstname = strtolower($_POST['firstname']);
		$email = $_POST['email'];
		$message = "<html><head><style>h1, h2, h3 { color: #850BC2; } h3 { text-decoration: underline; line-height: 25px; } #corps_msg { width: 600px; margin: 0 auto; border: 2px solid #850BC2; -moz-border-radius: 20px; -webkit-border-radius: 20px; -khtml-border-radius: 20px; -ms-border-radius: 20px; -o-border-radius: 20px; border-radius: 20px; padding: 10px 30px; } li, p { font-size: 16px; line-height: 30px; text-align: justify; }</style></head><body><div id='corps_msg'><h1>Hi!</h1><h2>New message!</h2><h3>From :</h3><ul><li><strong>Name:</strong> " . $name . "</li><li><strong>Firstname:</strong> " . $firstname . "</li><li><strong>E-mail:</strong> " . $email . "</li></ul><h3>Message recieved:</h3><p>" . $_POST['message'] . "</p></div></body></html>";
		$headers  = "From: " . $name . " " . $firstname . " <" . $email . ">\r\n";
		$headers .= "Reply-To: $email\r\n";
  		$headers .= "Content-Type: text/html; charset=\"utf-8\"\r\n";
  		$headers .= "Content-Transfer-Encoding: 8bit";

		mail($receiver, $subject, $message, $headers);

		$d['errors']['sendOK'] = $config['success'];
	}
	echo json_encode($d);
?>