Learning PHP

learning-php-arrays.php

<?php
  $fruits = array("bananas", "apples", "pears");
  echo 'I love eating ' . $fruits[1] . ' too!';
?>

<?php
  // On the line below, create your own associative array:
  $myArray = array(1, 2, 3, 4);

  // On the line below, output one of the values to the page:
  echo $myArray[0]; 

  // On the line below, loop through the array and output
  // *all* of the values to the page:
  foreach($myArray as $item){
    echo $item . "</br>";
  }

?>

<?php
  // This is an array using integers as the indices...
  $myArray = array(2012, 'blue', 5);

  // ...and this is an associative array:
  $myAssocArray = array('year' => 2012,
    'colour' => 'blue',
    'doors' => 5);

  // This code will output "blue"...
  echo $myArray[1];
  echo '<br />';

  // ... and this will also output "blue"!
  echo $myAssocArray['colour'];
?>

<?php    
  $food = array('pizza', 'salad', 'burger');
  $salad = array('lettuce' => 'with',
   'tomato' => 'without',
   'onions' => 'with');

  // Looping through an array using "for".
  // First, let's get the length of the array!
  $length = count($food);

  // Remember, arrays in PHP are zero-based:
  for ($i = 0; $i < $length; $i++) {
    echo $food[$i] . '<br />';
  }

  echo '<br /><br />I want my salad:<br />';

  // Loop through an associative array using "foreach":
  foreach ($salad as $ingredient=>$include) {
    echo $include . ' ' . $ingredient . '<br />';
  }

  echo '<br /><br />';

  // Create your own array here and loop
  // through it using foreach!
  $arr = array(1 => "a", 2 => "b", 3 => "c", 4 => "d");
  $lng = count($arr);

  foreach($arr as $el=>$i) {
    echo $i . ' elem is ' . $el;
  }
?>

<?php
  $deck = array(array('2 of Diamonds', 2),
    array('5 of Diamonds', 5),
    array('7 of Diamonds', 7),
    array('bla', 9));

  // Imagine the first chosen card was the 7 of Diamonds.
  // This is how we would show the user what they have:
  echo 'You have the ' . $deck[2][0] . '!';
?>

learning-php-classes.php

<?php
  class Person{
    // static functions can be executed without creating new instance of class
    public static function say(){
      echo "Here are my thoughts!";
    }
  }
  class Blogger extends Person{
    // constants can be accessed without creating new instance of class
    const cats = 50;
  }
  // executing static function directly from class definition (without created any class intance)
  Blogger::say();
  // getting constant variable directly from class definition (without creating any class instance)
  echo Blogger::cats;
?>

<?php 
  class Dog {
    public $isAlive = true;
    
    function __construct($name) {
      this->$name = $name;
    }
    
    public function bark() {
      echo 'Bark! Bark!';
    }
    // final keyword prevents from overriding it by child class
    public final function eat() {
      echo 'Yummy!';
    }
  }

  class Puppy extends Dog {
    // will override dog function
    public function bark() {
      echo 'Woof! Woof!';
    }
    
    // will not override parent class because of final keyword
    public function eat() {
      echo 'Mfmfmfmfmf!';
    }
  }
  
  $animal = new Puppy('Rex');

  $animal->bark(); // will return 'Woof! Woof!'
  $animal->eat(); // will return 'Yummy!'
?>