Pointers, Dynamic Arrays and Exception Handler.

[yAUfizwU]

So I have this activity for programming classI'm only allowed to place codes where it says "add code here". I managed to code some of it but when i tried to call the voids MilesPerrGallon and displaySort (pointed by comments), it always results of compile error. Can somebody pls help me

#include<iostream>
#include<iomanip>
using namespace std;


const int size=10;// use in menu[1] miles per gallon
typedef double *pointers;
void MilesPerrGallon(double *ptr1,double *ptr2);//process and display milespergallon
void MperG();//input miles and gallons and call function MilePerGallon
void getSort();//use dynamic array and a sort techniques to sort n values 
void displaySort(int *ptr,int smax);//displaying the vsorted values in descending order
char displayMenu(char *pt);//display the option on screen and return values 1,2 or 3 
//using a pointer variable

int  main()
{
   char ans,sagot;
   char *ptr;
   
//add code here
do{
	ptr=&sagot;
		do
		{
			ans=displayMenu(ptr);
		}while(*ptr!='1'&&*ptr!='2'&&*ptr!='3');
   
	switch(sagot)
	{
	//add code here
		case '1':  
		        {
					MperG();
				}
			break;
		case '2':  
				{			
					getSort();
				}
			break;
		case '3':
				{
		            cout<<"goodbye for now....\n";
		            system("pause");
		            exit(1);
				}
		            exit(1);
			break;
		 default:
				{
					cout<<"PAKYU";
				} 
			break;
	}
	
	
	do
	{
		cout<<"Try Again?[y/n]:";
		cin>>*ptr;
		*ptr=tolower(*ptr);
	}while(*ptr!='y'&&*ptr!='n');
	system("cls");
	}while(*ptr=='y');
	cout<<endl;
	cout<<"Thank you for using my program!";
	system("pause>0");
	return 0;
}
	

/////////////////////////
void MperG()
{double miles[size],gallons[size];
	int ctr;
	pointers milPtr,galPtr;
	int msize;

	system("cls");
	cout<<"COMPUTING FOR MPG : miles per gallon...\n";

	cout<<"MILES\n";
	//add code here
	while(true)
	{
	cout<<"Size must be from 5 to 15 only.\n\n";
	cout<<"Specify the size of the array: ";
	cin>>msize;
	try
		{
			if(msize>15||msize<3)
			 throw msize;
			 break;
		}
	catch(int x)
		{
			cout<<"\nSIZE MUST BE FROM 5 TO 15 ONLY!";
			system("pause>0");
			system("cls");
			continue;
		}
	}
	
	milPtr=new double[msize];
	galPtr=new double[msize];
	
	system("cls");
	cout<<"Miles\n";
	for(ctr=0;ctr<msize;ctr++)
	{
		bool ans=true;
		while(ans)
		{
			cout<<"\n\nThe number must be from 100-250 only.\n\n";
			cout<<"Miles ("<<ctr<<"): ";
			cin>>*(milPtr+ctr);

		try
			{
				if(*(milPtr+ctr)>250||*(milPtr+ctr)<100)
				 throw *(milPtr+ctr);
				 break;
			}
		catch(double e)
			{
				cout<<e<<" IS INVALID. THE NUMBER MUST BE FROM 100-250 ONLY!";
				system("pause>0");
				system("cls");
				continue;
			}
		}
	}


/*********************************************************/
cout<<"GALLONS\n";
	//add code here
system("cls");
cout<<"GALLONS\n";
cout<<"\n\nThe number must be from 5-25 only.\n\n";
	
	for(ctr=0;ctr<msize;ctr++)
	{
		bool ans=true;
		while(ans)
		{
			cout<<"Gallons ("<<ctr<<"): ";
			cin>>*(galPtr+ctr);

		try
			{
				if((*galPtr+ctr)>25||*(galPtr+ctr)<5)
				 throw *(galPtr+ctr);
				 break;

			}
		catch(double e)
			{
				cout<<e<<" IS INVALID. THE NUMBER MUST BE FROM 5-25 ONLY!";
				system("pause>0");
				system("cls");
				continue;
			}
		}
	}

//call MilePerrGallon here

}
////////////////////////
void MilesPerrGallon(double *ptr1,double *ptr2)
{

	double mpg[size];
	pointers mpgPtr;
   	 int index;
	//add code here
	system("cls");
	mpgPtr=&mpg[0];
	for(index=0;index<sz;index++)
		*(mpgPtr+index)=*(ptr1+index)/ *(ptr2+index);
	cout<<"MILES     /        GALLON     =   MPG\n";
	cout<<fixed<<setprecision(2); 
	for(index=0;index<sz;index++)
		{
			cout<<*(ptr1+index)
				<<setw(5)<<"/"
				<<setw(12)<<*(ptr2+index)
				<<setw(16)<<*(mpgPtr+index)
				<<endl;
		}
}
///////////////////////////////////////
void getSort()
{
	//add code here
	int srt;
	pointers srtPtr;
	int ssize;

	system("cls");
	cout<<"Sorting\n";
		cout<<"How many numbers would you like to sort? ";
		cin>>ssize;
	
	srtPtr=new double[ssize];
	cout<<"\n\n\nIndex\n";
	for(srt=0;srt<ssize;srt++)
	{
		bool ans=true;
		while(ans)
		{
			cout<<"Index ["<<srt<<"]: ";
			cin>>*(srtPtr+srt);

		try
			{
				if(*(srtPtr+srt)>250||*(srtPtr+srt)<100)
				 throw *(srtPtr+srt);
				 break;
			}
		catch(double e)
			{
				cout<<e<<" IS INVALID. THE NUMBER MUST BE FROM 100-250 ONLY!";
				system("pause>0");
				system("cls");
				continue;
			}
		}
	}


//call displaysort here

}


/////////////////////////
void displaySort(int *ptr,int smax)
{
	//add code here
	double srt[size];
	pointers srtPtr;
   	 int index;
   	 
	system("cls");
	srtPtr=&srt[0];
	cout<<"The "<<srt<<" numbers stored in decending order";
	for(index=0;index<smax;index++)
		*(srtPtr+index)=*(ptr+index);
	cout<<"Index ["<<srt<<"]: ";
	cout<<fixed<<setprecision(2); 
	for(index=0;index<smax;index++)
		{
			cout<<*(ptr+index)
				<<setw(5)<<"/"
				<<setw(16)<<*(srtPtr+index)
				<<endl;
		}
}
////////////////////////////////////////////

//////////////////////////////////////////
char displayMenu(char *pt)
{
	//add code here
	cout<<"MAIN MENU"<<endl
		<<"[1] - MPG (Miles Per Gallon)"<<endl
		<<"[2] - Sorting of Numbers"<<endl
		<<"[3] - Exit Program"<<endl
		<<"Enter Option: ";
	cin>>*pt;
   return *pt;
}

[ne555]

> when i tried to call (...) it always results of compile error.
when posting code, post the relevant parts. There is no point in posting code that does not cause the error.
when getting an error, post the full message. Verbatim.


your variable names are too "helpful" and "meaningful" to deduce their meaning.
MilesPerrGallon(miles, gallons);


About exceptions.
A function should throw an exception because it can't handle the situation (either don't have the knowledge or the resources to do it). The exception would propagate to the callers till somebody catches it and handled it.
I don't see the point in throwing if you are going to resolve it two lines below (like in line 150--157). As it is, there is no separation between the code that handles the normal flow and the exception one.

[yAUfizwU]

thanks for the help and advice ne555. I appreciate it.