user input loop

This is a discussion on user input loop within the C++ Programming forums, part of the General Programming Boards category; hey im havin a hell of a time doin sumthing that shud be easy ... ok the assignment is to ...

  1. #1
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    user input loop

    hey im havin a hell of a time doin sumthing that shud be easy ... ok the assignment is to prompt the user to input the number of grades they want to enter ... then im spose to get the average of those grades and output it all within a for loop .. . can u guys help me out?

  2. #2
    Handy Andy andyhunter's Avatar
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    Well, why don't you try something and then post what you did and then we will help. Becareful, posting questions like this with no work will get you flammed.

    Hint : use a for loop, I am sure you have gone over it in class.

  3. #3
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    ight heres wut i have done (in my main)

    int j;
    int loop_limit;
    int score;
    double average;

    cout << "How many scores do you want to enter? ";
    cin >> loop_limit;

    for (j = 1; j <= loop_limit; average = score / loop_limit, ++j)
    {cout << "Enter a score: ";
    cin >> score;
    average = score / loop_limit;
    }

    cout << average << endl;

  4. #4
    Handy Andy andyhunter's Avatar
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    Ok, before anyone flames please use code tags. Simply place [*code] the begginning and [*/code] (minus the asterisk)at the end of the code you submit to make it more readable.

    Now for your problem:

    1. use variable names that are helpful, j is not helpful.
    2. no one is going to do the assignment for you so I will point you in the right direction.

    Code:
    int main(void) {
    
              int currentScore, numberScores, score, total, average;
              cout << "Enter how many scores you wish to average:";
              cin >> numberScores;
    
              for(currentScore = 0; currentScore < numberScores; currentScore++) {
                            
                       //get the scores and add them to total
               }
    
               //calculate and display average
    
               return 0;
    }
    That should get you off to a good start. Happy coding

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    hey one more thing .. i just dont understand how to take in each score as being separate and add them together

  6. #6
    Guest Sebastiani's Avatar
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    well, you could add them right there in the loop to a 'total' (initialize to zero). you can use an array, too. also, you'll want to calculate the average *after* the loop terminates.
    Code:
    if( numeric_limits< byte >::digits != bits_per_byte )
        error( "program requires bits_per_byte-bit bytes" );
    24bbs.cpp

  7. #7
    Registered User jlou's Avatar
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    Code:
     int score = 0;
     int totalscore = 0;
    
    ...
    
      cin >> score;
      totalscore += score;
    Keep a running total of the scores, and divide that by the number of scores entered. Inside the loop this will be j, after the loop is done this will be loop_limit. If you aren't understanding why that works, think about it, then ask.

  8. #8
    Cat without Hat CornedBee's Avatar
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    i, j etc. are perfectly helpful names. Every programmer knows that a variable called i (or j, k, m, ... if i already exists) is a loop index.

    However, in C++ loop indices should be declared inside the loop:
    for(int i = 0; i < max; ++i)
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

  9. #9
    Handy Andy andyhunter's Avatar
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    However, in C++ loop indices should be declared inside the loop:
    I don't even need to say anything.

  10. #10
    Cat without Hat CornedBee's Avatar
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    Huh?
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

  11. #11
    Handy Andy andyhunter's Avatar
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    In the original code listing "int j" was just declared and then later on it was used in the loop. Thus the variable was viable for the entire function. I prefer not to use cryptic loop index names if their scope extends beyond the loop. Just a style point for me though.

  12. #12
    Cat without Hat CornedBee's Avatar
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    Yes, the code was very C-style in that regard. In C, the variable HAS to be declared at the start of the function, yet programmers didn't want to use long names for the indices, so they just assumed (mostly correctly) that anyone seeing them would know that they are indices.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

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