Conditions and if else statements Exercise

exercise.php

<?php
$currentKeys = 2;
$maxKeyCapacity = 2;
$currentPotions = 4;
$maxPotionCapacity = 5;
$currentInventoryCapacity = $currentKeys + $currentPotions;
$maxInventoryCapacity = 10;

// New item incoming
$newItemType = 'potion';

// Write your inventory code here
if($currentInventoryCapacity < $maxInventoryCapacity)
{
    switch($newItemType)
    {
        case 'potion':
        {
            if($currentPotions < $maxPotionCapacity)
            {
                $currentPotions++;
                $currentInventoryCapacity++;
                echo 'potion added to inventory<br/>';
            }
            else
            {
                echo 'You can not take more potions<br/>';
            }
            break;
        }

        case 'key':
        {
            if($currentPotions < $maxPotionCapacity)
            {
                $currentPotions++;
                $currentInventoryCapacity++;
                echo 'key added to inventory<br/>';
            }
            else
            {
                echo 'You can not take more keys<br/>';
            }
            break;
        }

        default:
        {
            echo 'item added to inventory<br/>';
            $currentInventoryCapacity++;
            break;
        }
    }
}
else
{
    echo 'The inventory is full<br/>';
}

// New item incoming
$newItemType = 'key';

// Copy the previous item inventory code here aswell
if($currentInventoryCapacity < $maxInventoryCapacity)
{
    switch($newItemType)
    {
        case 'potion':
        {
            if($currentPotions < $maxPotionCapacity)
            {
                $currentPotions++;
                $currentInventoryCapacity++;
                echo 'potion added to inventory<br/>';
            }
            else
            {
                echo 'You can not take more potions<br/>';
            }
            break;
        }

        case 'key':
        {
            if($currentKeys < $maxKeyCapacity)
            {
                $currentKeys++;
                $currentInventoryCapacity++;
                echo 'key added to inventory<br/>';
            }
            else
            {
                echo 'You can not take more keys<br/>';
            }
            break;
        }

        default:
        {
            echo 'item added to inventory<br/>';
            $currentInventoryCapacity++;
            break;
        }
    }
}
else
{
    echo 'The inventory is full<br/>';
}
?>