Stack & Const
Alright, this week is a big one — we're tackling two topics that'll seriously level up your C++ game. First, you're going to build your very first data structure from scratch: the stack. What's a data structure? It's just a clever way of organizing data so that certain operations become really fast. And the stack is one of the simplest ones — it works on the LIFO (Last In, First Out) principle. Think of a stack of plates: the last plate you put on top is the first one you take off, right? You'll build a stack class using dynamic memory, so all that new/delete stuff from last week? You're about to put it to real use.
Second, we're covering const correctness — this is a C++ superpower that lets you slap a "do not touch" sign on your data. The const keyword marks things as read-only, whether that's a variable, a function parameter, or even a whole method. And it's not just about being tidy — the compiler will actually catch bugs for you at compile time if you try to modify something you said was const. Pretty neat, right?
| Concept | What It Means | Why It Matters |
|---|---|---|
| Stack (LIFO) | Last In, First Out | Used in function calls, undo, parsing |
const variable | Value cannot change after initialization | Prevents accidental modification |
const reference | Cannot modify the referred-to variable | Avoids copies while protecting data |
const member function | Method promises not to modify the object | Enables calling on const objects |
By the end of this week, you'll see how these two things fit together beautifully — building efficient data structures while keeping your code safe and easy to understand.