Shopping Cart: Totals, Tax, and Discounts
Build the cart engine behind every checkout: line items, quantities, a discount rule, and a tax calc, all as testable objects.
What you'll be able to build
Build the cart engine behind every checkout: line items, quantities, a discount rule, and a tax calc, all as testable objects. Along the way you pick up real, transferable PHP skills, not just this one project:
- classes and interfaces
- array_reduce over line items
- money math without float errors (cents)
- a discount strategy via an interface
- iterating and summing
- formatted currency output
A course like this one
Yours is built from your own placement, so module count and depth will differ. This map shows what a intermediate-level PHP learner building Shopping Cart actually gets.
- Module 1: Values, variables, and echo5 lessons
Builds the script for your shopping cart.
- Module 2: Associative arrays and the array toolkit5 lessons
Builds the array pipeline workflow for your shopping cart.
- Module 3: Control flow, truthiness, and predicting output5 lessons
Builds the function that powers your shopping cart.
- Module 4: Functions, arrays, and reading errors5 lessons
Builds the reusable class for your shopping cart.
- Module 5: Classes, objects, and program design5 lessons
Builds the associative model for your shopping cart.
- Module 6: Shipping a reusable PHP tool3 lessons
Builds the command-line tool for your shopping cart.
How the lessons actually work
Every lesson has you predict what a piece of PHP code will output before you run it, then run it for real in your browser and fix what you got wrong. Each module ends in a challenge gate with hidden tests, so you can't advance until your code actually works. The course closes with a capstone that assembles everything into Shopping Cart, and a runnable proof page tied to your own code.
Common questions
How long does the Shopping Cart: Totals, Tax, and Discounts course take?
about 7 hours, across 6 modules and 28 lessons, at roughly 15 minutes per lesson. Your own course may run shorter or longer, since it's sized to your placement result, not a fixed template.
Do I need experience?
Some. This is an intermediate-tier PHP project, so it assumes you're comfortable with PHP basics and pushes past them.
How much does it cost?
$15 one-time, no subscription. The first module is free, so you can see exactly how the course teaches before you pay for the rest.