Simple Example for add / remove cart items

SimpleCart.php

<?php

// Products items
[
	"id" => 1,
	"name" => "test"
	"price" => 30
],
[
	"id" => 2,
	"name" => "test1"
	"price" => 40
]

// Clicks on Add to cart - 2
function addToCart ($productId, $price, $quantity)
{
	if (!isset($_SESSION['cart'])) {
		$_SESSION['cart'] = [];
	}
	
	$cart = $_SESSION['cart'];
	
	// Double check on product
	foreach ($cart as $index => $value) {
		if ($value['id'] === $productId) {
			return $cart;
		}
	}
	
	$cart = array_push($cart, [
		"id" => $productId,
		"price" => $price,
		"quantity" => $quantity,
	]);
	
	return $_SESSION['cart'] = $cart;
}

// click to remove from cart - 2
function removeFromCart ($productId) 
{
	$cart = $_SESSION['cart'];

	foreach ($cart as $index => $value) {
		if ($value['id'] === $productId) {
			unset($cart[$index]);

			break;
		}
	}
	
	return $_SESSION['cart'] = $cart;
}


// Cart items
$_SESSION['cart'] = [
	0 => [
		"id" => 1,
		"name" => "test"
		"price" => 30
	],
	1 => [
		"id" => 2,
		"name" => "test1"
		"price" => 40
	]
]