11.3. Implicit variable access¶
Actually, the new version of Time::print is more complicated than it
needs to be. We don’t really need to create a local variable in order to
refer to the instance variables of the current object.
If the function refers to hour, minute, or second, all by
themselves with no dot notation, C++ knows that it must be referring to
the current object. So we could have written:
void Time::print () {
cout << hour << ":" << minute << ":" << second << endl;
}
This kind of variable access is called implicit because the name of the object does not appear explicitly. Features like this are one reason member functions are often more concise than nonmember functions.
- after being granted permission
- Incorrect! You don't need "permission" to access member variables inside a member function.
- only inside of that specific member function
- Incorrect! You can access member variables implicitly inside any and all member functions.
- using dot notation
- Incorrect! You don't need to use dot notation to access variables implicitly.
- directly, without dot notation
- Correct! Implicit variable access allows us to access variables directly-- without using dot notation.
Q-1: Implicit variable access in member functions allows us to access member variables __________.
- Every time you are working with data structures!
- Incorrect! The scope resolution operator is not always necessary!
- When you implement member functions inside of the structure definition.
- Incorrect! When you write member functions inside of the structure definition, you do not need to specify the scope.
- When you implement member functions outside of the structure definition.
- Correct! When you write member functions outside of the structure definition, you need to specify the scope, hence the :: operator!
- Never! It is bad practice!
- Incorrect! The scope resolution operator is good practice when used correctly!
Q-2: When should you use the scope resolution operator ::?
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