Question

Define the missing member function. Use "this" to distinguish the local member from the parameter name.

Answer 1

Answer:

Here is the complete member function:

void CablePlan::SetNumDays(int numDays) {   //member function of class CablePlan which take numDays as parameter

this->numDays = numDays;   // refers to the fields numDays of CablePlan  class using this keyword

return;  }

Explanation:

The complete program is:  

#include <iostream>  //to use input output functions

using namespace std; //to identify objects like cin cout

class CablePlan{  //class

public:  //public methods of class

void SetNumDays(int numDays); //method of class CablePlan that takes numDays as parameter to set the days

int GetNumDays() const;  // method of class CablePlan to get no of days

private:  //private data member of class CablePlan

int numDays;  //private data member of class CablePlan that holds no of days

};

// FIXME: Define SetNumDays() member function, using "this" implicit parameter.

void CablePlan::SetNumDays(int numDays) { /

this->numDays = numDays;     // used to refer to numDays variable of CablePlan class using this keyword

return;}  

int CablePlan::GetNumDays() const {  //define member function GetNumDays

return numDays;}  

int main() {  //start of main function

CablePlan house1Plan;  //creates object of CablePlan class

house1Plan.SetNumDays(30);  //uses object to call member function of  CablePlan passing value 30 to it in order to set no of days

cout << house1Plan.GetNumDays() << endl;  //uses object to call member function of  CablePlan to get the no of days (numDays)

return 0;}

Here this keyword is used to refer to the field i.e. numDays of CablePlan class. This distinguishes local member numDays  from parameter numDays using this with -> symbol.  

'this' pointer retrieves the object's numDays  which is hidden by the local variable numDays . The output of this program is:

30

Answer 2

Answer:

this.numDays = numDays;

Explanation:

You just need one line of code.  "this." to access the class member, and the "." is the member access operator.