Thread: char arrays, pointers, etc, could use help badly

Code:

#include <iostream.h>
using namespace std;

void displayDay(char *ptr);
void displayDayAddress(char *ptr);

int main(){
	char *days[] = {"Sunday",
					"Monday",
					"Tuesday",
					"Wednesday",
					"Thursday",
					"Friday",
					"Saturday"};     //array of char pointers
	int selectedDay;
	char *ptr;       //character pointer
	
	cout << "OUTPUT FOR PROBLEM #6a and #6b: " << endl;
	cout << "What day is it today? (1 - 7): ";
	cin >> selectedDay;
	ptr = days[selectedDay - 1];        //store address of the given array element in ptr
	displayDay(ptr);
	
	cout << "\n\nOUTPUT FOR PROBLEM #6c: " << endl;
	cout << "This day's address begins at: ";
	displayDayAddress(ptr);
	
    return 0;
} //end int main


void displayDay(char *ptr){
	cout << "Today's day is " << ptr;
	 
} //end void displayDay


void displayDayAddress(char *ptr){
	cout << &ptr;
}

For some reason I can't do what I want to do. What I want to do:

-Send into a function that large *char array of months, and an int
-In that function, the user will input a number into this int
-That day is called from the function. For instance, entering 2 will display Monday

-Then I need to make another function that outputs the address of the first character of the day inputted.


However, I can't get this to work right! I can't pass the values correctly so the majority of it is in main!! I could really use some assistance

i'm a terrible person, as i am too lazy to run this through a c++ compiler. how about some error messages/bad output?

void displayDayAddress(char *ptr){
cout << ptr;
}

that should work (i think, maybe?)

&ptr is the memory location of the pointer
ptr is the value of the pointer (the address of the item)
*ptr is the value of the address the pointer points to

buggered pointer rules...

i don't really see why you want to break your program down into smaller functions, unless you're just appeasing a professor ;p - it doesn't look so bad as it is. in fact, i wouldn't even bother to make any functions for that.

if you've gotta, then just write the functions out... and pass the address of the variables that will store the input to the function as pointers.

Works fine to me. But I put it into a loop, and wrote a function "range" to verify the user didn't type '0', or whatever (guess what "days[-1]" would print??)

Code:

using namespace std;

bool range(int value, int low, int high);
void displayDay(char *ptr);
void displayDayAddress(char *ptr);

int main(){
	char *days[] = {"Sunday",
					"Monday",
					"Tuesday",
					"Wednesday",
					"Thursday",
					"Friday",
					"Saturday"};     //array of char pointers
	int selectedDay;
	char *ptr;       //character pointer

	cout << "OUTPUT FOR PROBLEM #6a and #6b: " << endl;
	cout << "What day is it today? (1 - 7): ";
 	cin >> selectedDay;

  while(range(selectedDay, 1, 7)) {
	 ptr = days[selectedDay - 1];        //store address of the given array element in ptr
	 displayDay(ptr);
	 cout << "\n\nOUTPUT FOR PROBLEM #6c: " << endl;
	 cout << "This day's address begins at: ";
	 displayDayAddress(ptr);
     cout << "OUTPUT FOR PROBLEM #6a and #6b: " << endl;
	 cout << "What day is it today? (1 - 7): ";
  	 cin >> selectedDay;
     }
    return 0;
} //end int main


void displayDay(char *ptr){
	cout << "Today's day is " << ptr << endl;
	 
} //end void displayDay


void displayDayAddress(char *ptr){
	cout << &ptr << endl;
}

bool range(int value, int low, int high){
 if(value >= low && value <= high)
  return true;

 return false;
}

Ah, noticed the address bug...

void displayDayAddress(char *ptr){
cout << (int)ptr << endl;
}