Functions and Reusable Logic
Learn C++ functions by building a smart home thermostat system that can make comfort decisions for multiple rooms and days.
The project
In the previous lesson, you built a smart thermostat that decided whether to turn on the fan, heater, or AC depending on the temperature, season, and whether it was peak hours.
But here’s the challenge: right now, your code works for only one room at a time. What if you want to check the comfort level in the living room, bedroom, and kitchen, each with different temperatures? And what if you want the same room to adjust its temperature based on who is there at that moment?
Repeating the same decision logic over and over is messy, error-prone, and difficult to update. Instead, C++ gives us a superpower: functions—reusable blocks of logic that we can call anytime.
The programming concept
Remember how the built-in functions like cin.clear() and setprecision() feel like little magic boxes that do something when you use them? Of course, someone had to define how those work before you could use them. But what if you could create your own? After all, no language can possibly come with every possible function ...