How to count up values from a while statement?

[Anonomys]

#include <iostream>
using namespace std;
int main()
{
    int numberOfItems;
    int count; //loop counter for the loop
    int caloriesForItem;
    int totalCalories;
    cout << "How many items did you eat today? ";
    cin >> numberOfItems;
    cout << "Enter the number of calories in each of the "
        << numberOfItems << " items eaten: " << endl;
//My Code
     int i = 1;
    while (i <= numberOfItems)
    {
        cout << "Total calories for item " << i << " : " ; i++;
        cin >> caloriesForItem;
    }

totalCalories = //sum of  the values inputed;

//My Code
        cout << "Total calories eaten today = " << totalCalories;
return 0;
}

here is the code , i need to be able to sum the values inputted by user. Can anyone help ?

[keskiverto]

Isn't 'totalCalories' the "sum of the values inputed"?
What if you add every new item to 'totalCalories'?


PS. What if number of items is 0; what is 'totalCalories' then?

[salem c]

Start with
int totalCalories = 0;

Inside the loop, so
totalCalories += caloriesForItem;


> int count; //loop counter for the loop
No it isn't. You don't use it.

> int i = 1;
> while (i <= numberOfItems)
A for loop is much better when you know in advance how many times you want to iterate.
Your badly placed i++ in your code is a bug waiting to happen.

for ( int i = 1 ; i <= numberOfItems ; i++ )
wraps up the whole loop into a single easy to recognise code.

[Anonomys]

@salem c ,I understand what you getting at with the for loop.

I have to do both for and while loop , they both are done , i just needed to know how to calculate the totals on the total calories, i'll use your above message, thank you!


p.s. Im new at this , so just bare with me :P

I got the code and then within the //My Code blocks , i was needed to write a loop for the total of items enter and then to have the sum of the total calories for each item

#include <iostream>
using namespace std;
int main()
{
    int numberOfItems;
    int count; //loop counter for the loop
    int caloriesForItem;
    int totalCalories;
    cout << "How many items did you eat today? ";
    cin >> numberOfItems;
    cout << "Enter the number of calories in each of the "
        << numberOfItems << " items eaten: " << endl;
//My Code
     int i = 1;
    while (i <= numberOfItems)
    {
        cout << "Total calories for item " << i << " : "; i++;
        cin >> caloriesForItem;
        totalCalories += caloriesForItem;
    }



//My Code
        cout << "Total calories eaten today = " << totalCalories;
return 0;
}

so i changed it to this, its working but only 1 problem.

I have to input 7 items , it works
then
items are
120
60
150
600
1200
300
200
I enter them and get the value of 2630.
but im requested to have 2631? Its their error right?

[Anonomys]

@salem c

#include <iostream>
using namespace std;
int main()
{
    int numberOfItems;
    int count; //loop counter for the loop
    int caloriesForItem;
    int totalCalories;
    cout << "How many items did you eat today? ";
    cin >> numberOfItems;
    cout << "Enter the number of calories in each of the "
        << numberOfItems << " items eaten: " << endl;
//My Code
    for (int i=1; i <= numberOfItems; i++)
    {
        cout << "Total calories for item " << i << " : " ;
        cin >> caloriesForItem;
        totalCalories += caloriesForItem;
    }




//My Code
        cout << "Total calories eaten today = " << totalCalories;
return 0;
}

here is my for loop

[MikeyBoy]

What value do you think totalCalories will have before the first time totalCalories += caloriesForItem; (line 18) is executed?

What value do you think it will have immediately after the first time that line is executed?

(Hint: You've completely ignored something important @salem c told you.)

[Anonomys]

@MikeyBoy , the value that it had was 16 everytime and I couldn't figure out why, i did try
int totalCalories=0; before , but i still couldn't figure out exactly how to count them up together

[salem c]

I have to input 7 items , it works
then
items are
120
60
150
600
1200
300
200
I enter them and get the value of 2630.
but im requested to have 2631? Its their error right? 

C'mon - this is basic junior maths. You don't need a program or even a calculator.
7 values all with 0 in the units, how do you expect to wind up with a result having a 1 in the units.

Either your values are not what you're supposed to type in, or someone's expectation of the result is wrong.

[seeplus]

You should always initialise variable when they are defined. By default they are not initialised and could have any value.

#include <iostream>
using namespace std;

int main()
{
	int numberOfItems {};
	int caloriesForItem {};
	int totalCalories {};

	cout << "How many items did you eat today? ";
	cin >> numberOfItems;

	cout << "Enter the number of calories in each of the "
		<< numberOfItems << " items eaten\n";

	//My Code
	for (int i = 1; i <= numberOfItems; ++i)
	{
		cout << "Total calories for item " << i << " : ";
		cin >> caloriesForItem;
		totalCalories += caloriesForItem;
	}

	//My Code
	cout << "Total calories eaten today = " << totalCalories << '\n';
	return 0;
}

[keskiverto]

The input can fail. Therefore, it should be tested and one has to decide how failure is handled. For example:

int count {};
while ( count < numberOfItems &&
        (cout << "Total calories for item " << (count+1) << " : ") &&
        cin >> caloriesForItem )
{
  ++count;
  totalCalories += caloriesForItem;
}
cout << "Total calories for " << count << " items eaten today = " << totalCalories << '\n';