PHP Tutorial: Building a Shopping Cart 🛍️

Welcome to our comprehensive PHP tutorial where we'll build a shopping cart from scratch! By the end of this guide, you'll have a solid understanding of PHP and how to implement it in a real-world project. Let's get started! 🎯

Getting Started 👋

Before we dive in, ensure you have a local development environment set up. We recommend using XAMPP or MAMP.

Variables and Data Types 📝

In PHP, variables are used to store data. Here are some basic data types you'll encounter:

string: A sequence of characters, such as "Hello, World!".
integer: Whole numbers, like 123 or -100.
float: Decimal numbers, represented as 12.34 or 0.0001.
boolean: True or false values, like true or false.
array: A collection of values, such as $colors = ["red", "blue", "green"].

Creating a Basic HTML Layout 💻

Our shopping cart will have a simple HTML layout to display products, add to cart, and view cart. Here's a basic structure:

html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>My Shopping Cart</title>
</head>
<body>
    <!-- Add your PHP code within the body tags -->
</body>
</html>

Including PHP Code in HTML 🔗

To use PHP in our HTML file, we'll use the <?php and ?> tags. PHP code within these tags will be executed by the server before the HTML is displayed to the user.

html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>My Shopping Cart</title>
</head>
<body>
    <?php
        // Your PHP code goes here
    ?>
</body>
</html>

Creating the Products Array 🛍️

Let's start by creating an array with some sample products:

php

<?php
$products = [
    [
        "name" => "Product 1",
        "price" => 10.99,
        "quantity" => 5
    ],
    [
        "name" => "Product 2",
        "price" => 15.99,
        "quantity" => 3
    ]
];
?>

Displaying Products 📝

Now, let's display the products using a loop:

php

<?php
foreach ($products as $product) {
    echo "<h2>{$product["name"]}</h2>";
    echo "<p>Price: {$product["price"]}</p>";
    echo "<p>Quantity: {$product["quantity"]}</p>";
}
?>

Adding Products to the Cart 🛒

To add products to the cart, we'll create an empty $_SESSION variable:

php

<?php
session_start();

if (!isset($_SESSION["cart"])) {
    $_SESSION["cart"] = [];
}
?>

Now, let's create a function to add products to the cart:

php

function addToCart($productId) {
    global $_SESSION;

    if (!isset($_SESSION["cart"][$productId])) {
        $_SESSION["cart"][$productId] = 1;
    } else {
        $_SESSION["cart"][$productId]++;
    }
}

Viewing the Cart 🛒

To display the cart, we'll create a function to get the cart data:

php

function getCartData() {
    global $_SESSION;
    return $_SESSION["cart"];
}

Now, let's display the cart data:

php

<?php
$cart = getCartData();
if (!empty($cart)) {
    echo "<h2>Cart</h2>";
    foreach ($cart as $productId => $quantity) {
        echo "<p>Product ID: {$productId}</p>";
        echo "<p>Quantity: {$quantity}</p>";
    }
}
?>

Quiz Time 🎓

That's it for today! In the next lesson, we'll add more features to our shopping cart, like calculating the total cost and handling product removal. 📝 Stay tuned!