whats the error in this program?

[kamilhassaan]

in this program we are supposed to enter numbers greater than or equal to 0. if we enter a number lesser than 0, the program should end and then display the total amount of positive numbers that i entered.

#include <iostream>
using namespace std;
int main ()
{
	int number=0,total=0;
	
	cout<<"Type a number : ";
	cin>>number;
	
	while(number>=0)
	{
		cout<<"Type a number : ";
		cin>>number;
		
		total=number+1;
	}
	
	cout<<total;
	
	return 0;
}

[coder777]

Move line 15 before line 12.

And: total+=number+1;

[kamilhassaan]

something is still not right. let me rephrase what i mentioned above. if i enter any 5 positive numbers and after that if i enter -1, the program should display 5. similarly if i enter any 15 positive numbers the program should display 15

[doug88dg]

You still have work to do. Providing cin>> with a numeric string will not automatically convert it to its intended binary value. Typing "-1" will not give you a negative integer as it is still in string form. Instead you get a positive value of 0x2D31. I should also mention entering any more than 8 digits will likely cause this code to crash due to a memory access violation.

[E0p9LyTq]

kamilhassaan wrote:

if i enter any 5 positive numbers and after that if i enter -1, the program should display 5. similarly if i enter any 15 positive numbers the program should display 15

#include <iostream>

int main ()
{
   int number = 0;
   int total = 0;

   while(true)
   {
      std::cout<<"Type a number : ";
      std::cin>>number;

      if (number < 0)
      {
         break;
      }

      total++;
   }

   std::cout << "\nThe total is: " << total << std::endl;

   return 0;
}

[ne555]

while( std::cin>>number and number>=0 )

[doug88dg]

This code should do the job

#include <iostream>
using namespace std;
int main()
{
	int total = 0;
	// number should be a char array
	char number[24];

	while (true)
	{
		cout << "Type a number : ";
		cin >> number;
		//check for negative number
		if (number[0] == '-')
			break;
		 total++;
	}

	cout << total;

	return 0;

[Jaybob66]

doug88dg is incorrect, cin will read negative values.

also, reading the comments here i feel the need to point out there are two type of while loop in the world. "while" and "do while" (aka repeat until)

if you definitely want to execute the loop at least once, go for do while, otherwise use the normal while.

#include <iostream>
using namespace std;
int main ()
{
   int number=0,total=0;

   do
   {
      cout<<"Type a number : ";
      cin>>number;

      if (number>=0)
         ++total;

   } while(number>=0)

   cout << total;

   return 0;
}

[doug88dg]

I stand corrected. Jaybob66's code will work, though I should point out that problems may occur if anything other than a number is given. This code is a little bulkier, but is more stable.

#include <iostream>

using namespace std;

int main()
{
    int total = 0;
    int number;
    char buf[16] = { 0 };
    bool sign;

    do
    {
        cout << "Type a number : ";
	cin >> buf;
	number = 0;
	sign = false;
		
	for (int i = 0; i < 16; i++)
	{
	        if (buf[i] >= 0x30 && buf[i] <= 0x39)
		    number = number * 10 + buf[i] - 0x30;
		if (buf[i] == '-' && number == 0)
		    sign = true;
		buf[i] = 0;
         }
		
	number = sign ? -number : number;
	
	if (number > 0)
		total++;
			
	}while (number >= 0);

	cout << total;

	return 0;
}

Jaybob66, thanks for the correction.

[kamilhassaan]

I appreciate you guys trying to help, but the thing is, I started C++ less than a week ago. I am only aware of the following functions;
1. If-Else
2. Nested if
3. While loop
4. For loop

I only know the basics of these functions. And my teacher didn't teach us the "Do-While Loop".
My teacher did not tell us anything about using "std" anywhere else other than "using namespace std;".

So, can you guys please make it simple? Thank you!