How do you create an object on the stack in C++?

Just declare it with constructor arguments: Vehicle v(4); — it lives on the stack and is destroyed automatically when it goes out of scope.

int main() {
    Vehicle v(4);   // create a Vehicle with 4 wheels
    v.show();       // call a method with dot notation
    return 0;
}
// v is automatically destroyed here, at end of scope

Output:

Vehicle has 4 wheels.

Key points:

• No new keyword needed
• The object is allocated on the stack
• It's destroyed automatically at the end of its scope (this automatic cleanup is the heart of RAII)
• Use . to access its members

Go deeper:

• Stack-based memory allocation — Wikipedia — how automatic (stack) storage grows and unwinds.