PHP Tutorial: Classes and OOP

PHP Tutorial: Classes and OOP 

 

<?php
//PHP Tutorial: Classes and OOP
//The first thing you do is to define the class:
class cow
{
}
//Next, we'll create our first function - this is defined exactly the same as if you were not using classes:
// First we define the class
class cow
{
    // Define the function moo() - no parameters    
    function moo()
    {
        // Define the variable
        $sound = 'Moooooo';
        return $sound;
    }
}
//create the new class object 'in' a variable
// Create new cow object
$daisy = new cow;
//then call the moo() function
echo $daisy->moo();

//If you put this code together then, you will get something like this:
// First we define the class
class cow
{
    // Define the function moo() - no parameters    
    function moo()
    {
        // Define the variable
        $sound = 'Moooooo';
        return $sound;
    }
}
// Create new cow object
$daisy = new cow;
echo $daisy->moo();

//Ex. more functions
// First we define the class
class cow
{
    var $eaten;

    // Define the function moo() - no parameters    
    function moo()
    {
        // Define the variable
        $sound = 'Moooooo<br />';
        return $sound;
    }
    function eat_grass($colour)
    {
        if ($colour == 'green')
        {
            // cow is happy
            $this->eaten = true;
            return $this->moo();
        }
    }

    function make_milk()
    {
        if ($this->eaten)
        {
            return 'Milk produced<br />';
        }
        else
        {
            return 'cow has not eaten yet<br />';
        }
    }
}

//call these functions and try out the new class
// Create the cow object daisy
$daisy = new cow;
echo $daisy->moo();
echo $daisy->make_milk(); // Cow has not eaten yet
$daisy->eat_grass('green');
echo $daisy->make_milk(); // Milk produced

//final version
// First we define the class
class cow
{
    var $eaten;

    // Define the function moo() - no parameters    
    function moo()
    {
        // Define the variable
        $sound = 'Moooooo<br />';
        return $sound;
    }
    function eat_grass($colour)
    {
        if ($colour == 'green')
        {
            // cow is happy
            $this->eaten = true;
            return $this->moo();
        }
    }

    function make_milk()
    {
        if ($this->eaten)
        {
            return 'Milk produced<br />';
        }
        else
        {
            return 'cow has not eaten yet<br />';
        }
    }
}

// Create the cow object daisy
$daisy = new cow;
echo $daisy->moo();

echo $daisy->make_milk(); // Cow has not eaten yet
$daisy->eat_grass('green');
echo $daisy->make_milk(); // Milk produced
?>