Wu Yuxiong - born natural learning PHP Development: Data Types

<?php
$x = "Hello world!";
echo $x;
echo "<br>";
$x = 'Hello world!';
echo $x;
?>

? < PHP
 $ the X- = 5985 ;
 var_dump ( $ the X- );
 echo "<br>" ;
 $ the X- = -345; // negative 
var_dump ( $ the X- );
 echo "<br>" ;
 $ the X- = 0x8C; // hexadecimal number 
var_dump ( $ the X- );
 echo "<br>" ;
 $ the X- = 047; // octal 
var_dump ( $ the X- );
 ?>

<?php
$x = 10.365;
var_dump($x);
echo "<br>";
$x = 2.4e3;
var_dump($x);
echo "<br>";
$x = 8E-5;
var_dump($x);
?>

<?php
$cars=array("Volvo","BMW","Toyota");
var_dump($cars);
?>

<?php
class Car
{
    var $color;
    function __construct($color="green") {
        $this->color = $color;
    }
    function what_color() {
        return $this->color;
    }
}
?>

<?php
$x="Hello world!";
$x=null;
var_dump($x);
?>