laravel_ioc_container_di.php

<?php
require __DIR__.'/vendor/autoload.php';

interface Greetable
{
    public function greet();
}

class Hello implements Greetable
{
    /**
     *
     */
    public function greet()
    {
        echo 'Hello';
    }
}

class Bye implements Greetable
{
    /**
     *
     */
    public function greet()
    {
        echo 'Bye';
    }
}

class Bar
{
    /**
     * @var Greetable
     */
    protected $greeter;

    /**
     * @param Greetable $greeter
     */
    public function __construct(Greetable $greeter)
    {
        $this->greeter = $greeter;
    }

    /**
     *
     */
    public function say()
    {
        $this->greeter->greet();
        echo PHP_EOL;
    }
}

$app = new \Illuminate\Foundation\Application();
//$app->make('Bar')->say();

// bind Greetable class name
$app->bind('Greetable', 'Hello');
$app->make('Bar')->say();

// bind Greetable factory
$app->bind('Greetable', function($app) {
    return new Hello();
});
$app->make('Bar')->say();

// bind Bar factory
$app->bind('Bar', function($app) {
    return new Bar($app->make('Hello'));
});
$app->make('Bar')->say();