sentinel controlled looop

sentinel controlled while loop.
need to read numbers from an input file until i read a certain number say 1234.
then output the total count of the numbers that have been processed.

 const int SENTINEL = 99999;

int main(void)
{
   int numbers;
   int totalCount;


numbers = 0;

inFile >> numbers;

while (numbers!=SENTINEL)
    totalCount+= numbers;
 inFile >> numbers;

closed account (28poGNh0)

Let's say that you have a file.txt that containes 15 numbers like this

15 30 51 24 13 9 55 21 98 54 41 20 77 54 21

I suggest this program

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

int main()
{
    ifstream inFile("file.txt");

    int HOW_MANY_NUMBER_I_WANT_TO_READ = 0;

    cout << "How many numbers you want to read -> ";
    cin >> HOW_MANY_NUMBER_I_WANT_TO_READ;

    int number = 0;
    int totalCount = 0;

    for(int i=0;i<HOW_MANY_NUMBER_I_WANT_TO_READ;i++)
    {
        inFile >> number;
        totalCount += number;

        cout << "The number " << i+1 << " is : " << number << endl;
        cout << "The total count is : " << totalCount << endl << endl;
    }

    return 0;
}

and I hope It helps

Ganado (6784)

Techno01:
Quick question, how does it know that the "number" variable corresponds to each number in the .txt file?

Lowest0ne (1536)

Techno01's example does not use a sentinel, probably not a good idea to use that code.

Your program is missing brackets, should work though. I assume you haven't posted all of the code:

const int SENTINEL = 99999;

int main(void)
{
    /* ... */
    
    int totalCount = 0;

    int numbers;
    inFile >> numbers;
    
    while (numbers!=SENTINEL) //  hope the sentinel is in the file!!!
    {
        totalCount+= numbers;
        inFile >> numbers;
    }
    
    /* ... */
}

Last edited on

closed account (28poGNh0)

Maybe you're half right @LowestOne .I thought that he want to get 1234 number from the file wich is SENTINEL.
Now I think he want to get total counts of numbers until he find SENTINEL am I right?

If that the case my code will be suggested like this:

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

int main()
{
    ifstream inFile("file.txt");

    const int SENTINEL = 21;

    int numbers;
    int totalCount;

    numbers = 0;
    totalCount = 0;// must initialised too because It takes a random value and will be countd

    // inFile >> numbers; no need for this one
//if we get numbers = SENTINEL we wont get any totalCount

    while (numbers!=SENTINEL)
    {
        inFile >> numbers;
        totalCount+= numbers;
    }

    cout << "Total count = " << totalCount << endl;

    return 0;
}

I hope that helps

hogwheeley (17)

sorry for the vagueness.

i have an input file that has a bunch of numbers like this

1213
1456
1256
1678
1245
3456
1111

i need those numbers written on the screen like this

number number number number number

number number number number number

rows of 5 numbers untill the 1111 number is reached.

then i need total count after all them.

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sentinel controlled looop