Unit Converter: A Tiny CLI Tool
Build a converter that turns Celsius to Fahrenheit, miles to km, and more, dispatching on a unit name. Your first real command-style tool.
What you'll be able to build
Build a converter that turns Celsius to Fahrenheit, miles to km, and more, dispatching on a unit name. Your first real command-style tool. Along the way you pick up real, transferable PHP skills, not just this one project:
- functions with typed parameters
- match expressions for dispatch
- float math and rounding
- associative arrays as a lookup table
- number_format for clean output
- default parameter values
A course like this one
Yours is built from your own placement, so module count and depth will differ. This map shows what a beginner-level PHP learner building Unit Converter actually gets.
- Module 1: Values, variables, and echo6 lessons
Builds the script for your unit converter.
- Module 2: Associative arrays and the array toolkit6 lessons
Builds the array pipeline workflow for your unit converter.
- Module 3: Control flow, truthiness, and predicting output6 lessons
Builds the function that powers your unit converter.
- Module 4: Functions, arrays, and reading errors6 lessons
Builds the reusable class for your unit converter.
- Module 5: Classes, objects, and program design6 lessons
Builds the associative model for your unit converter.
- Module 6: Shipping a reusable PHP tool3 lessons
Builds the command-line tool for your unit converter.
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 Unit Converter, and a runnable proof page tied to your own code.
Common questions
How long does the Unit Converter: A Tiny CLI Tool course take?
about 8.5 hours, across 6 modules and 33 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?
No. This is a beginner-tier PHP project, built for someone writing their first real PHP programs.
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.