Shadowing Resolution

Question

Problem: Shadowing Resolution. Solve this hands-on electronics task on EWskills.

Accepted Answer

#include 

class Timer {
private:
    int period = 0;

public:
    void setPeriod(int period) {
        // 'this->period' refers to the member variable.
        // 'period' refers to the local argument.
        this->period = period;
    }

    void log() {
        std::cout << "Timer Period: " << period << " ms" << std::endl;
    }
};

int main() {
    Timer t;
    int N;
    if (!(std::cin >> N)) return 0;

    for (int i = 0; i < N; ++i) {
        int p;
        std::cin >> p;
        t.setPeriod(p);
        t.log();
    }
    return 0;
}

Explanation & Logic Summary:

Shadowing: When a local variable (argument) has the same name as a member variable, the compiler prioritizes the local one.
The Fix: this is a pointer to the object itself. this->period explicitly tells the compiler "go to the object's memory and find the variable named period," bypassing the local argument scope.
Why do this? It avoids awkward naming conventions like void setPeriod(int p) or void setPeriod(int _period). The code is self-documenting: you are setting the period with a period.

Firmware Relevance & Real-World Context:

Driver APIs: In large projects, keeping variable names consistent (e.g., always using frequency instead of freq, f, frq) reduces cognitive load. Using this-> allows you to maintain that consistency in both the public API and the internal storage.

189. Shadowing Resolution