Thread: Problem with pointers and functions

We're covering pointers in my C++ class, and just got done studying functions. I'm trying to write a program that uses cin.get() to read input (yes, I know this must be a char value). The cin.get() must be included in the getInteger function, not in main. It must return the value to main, so getInteger can't be a void function. Additionally, num must be a pointer to the integer the user inputs, and must be a parameter of function getInteger. Here's the code I've written. It runs, but terminates after I input an integer. Any ideas would be GREATLY appreciated. I'm completely stuck.

Code:

#include <cctype>
#include <iostream>

using namespace std;

int getInteger(int *num);

int main()
{
	int input;
	int *param;
	cout << "Enter an integer with a leading + or - sign." << endl;
	input=getInteger(param);
	cout << "The integer you entered is " << input;

	return 0;
}

int getInteger(int *num)
{	
	char c;
	int sign;
	int rtrn;
	int value=0;

	cin.get(c);
	do
		cin.get(c);
	while(isspace(c));

	if (!isdigit(c) && !cin.eof() && c!='+' && c!='-')
	{
		rtrn=0;
	}
	else
	{
		if(c=='-')
			sign=(-1);
		else
			sign=1;
		
		if(c=='-' || c=='+')
			c=cin.get();
		
		while(isdigit(c))
		{
			value=10*value+c-'0';
			c=cin.get();
		}
		value=value*sign;
		
		if(!cin.eof())
			cin.putback(c);
		
		rtrn=c;
	
	}
	*num=value;
	return rtrn;
}