如何使"使用未初始化的值"警告消失？

int myVar = 0;

class MyClass {
public:
    MyClass() {
        myVar = 0;
    }

private:
    int myVar;
};

void myFunction(int& myVar) {
    myVar = 0;
}

int main() {
    int myVar;
    myFunction(myVar);
    return 0;
}

int myVar;
if (condition) {
    myVar = 0;
}

int myVar;
for (int i = 0; i < 10; i++) {
    myVar = 0;
}