Thread: how to print and save?

  1. #16
    C++ Witch laserlight's Avatar
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    I suggest that you post your current code. Indent it more consistently, please.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  2. #17
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    here's my current code..


    Code:
    #include<stdio.h>
    float enter_hours(float w);
    float calculateCharges(float x,float y);
    
    int main ()
    
    {
    
     for (int count=1;count<=3;count++);
     {
    	float a;
    	float p;
    	float q;
    
    	printf("Car\tHours\tCharges\n");
    	printf("%d\t%.1f\t%.2f",count,enter_hours(a),calculateCharges(p,q));
    	count++;
     }
    return (0);
    }
    
    float enter_hours(float w)
    {
      scanf("%f",&w);
      return w;
    }
    
    float calculateCharges(float n,float x)
    {
      if (x<=3){
      return 2.00;
      }
    
      if (x>3 && x<24){
      n=x-3;
      return 2.00+0.50*n;
      }
    
      if (x==24){
      return 10.00;
      }
     return x;
    }

  3. #18
    C++ Witch laserlight's Avatar
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    You should use variable names that are more descriptive.

    The main problem at this point is that you are reading in the input while calculating and printing the output. You probably should be reading the input into an array, then do the calculation and output using the array.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  4. #19
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    i'm so so so sorry..

    but i really don't understand..

    the things that you have kindly explained to me seems so hard for me to interpret...

    i can hardly understand what you are talking..

    i'm so sorry..

    could you explain or show me what should i do to undo these warnings...?

    "possible use of 'p' before definition in main ()"

    thanks..

  5. #20
    Hurry Slowly vart's Avatar
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    Code:
    float enter_hours(float w)
    {
      scanf("&#37;f",&w);
      return w;
    }
    Why do you pass w as a parameter? Do you use its value? No.
    so it should be like that:
    Code:
    float enter_hours(void)
    {
      float w;
      scanf("%f",&w);
      return w;
    }
    Code:
    float calculateCharges(float n,float x)
    What is n and what is x?

    Shouldn't be only one input - number of hours spent on the parking?
    Where do you initialize this value before calling your function?

    What should be the output for 23.5 hours parking?

    How do you transfer value returned by enter_hours to the calculateCharges?
    Where do you calculate Total?
    All problems in computer science can be solved by another level of indirection,
    except for the problem of too many layers of indirection.
    – David J. Wheeler

  6. #21
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    Quote Originally Posted by vart View Post
    Code:
    float enter_hours(float w)
    {
      scanf("&#37;f",&w);
      return w;
    }
    Why do you pass w as a parameter? Do you use its value? No.
    yes.. i did use it.. w supposed to be hours input by user..
    it is used to calculate the charge..

    What is n and what is x?
    i posted the question on other thread titled "assistance in function"...

    please have a look at there and it may kind of explain most of the things you have asked..

    Shouldn't be only one input - number of hours spent on the parking?
    there are 3 cars to be included in the systems..

    What should be the output for 23.5 hours parking?
    2.00 + (23.5-3)*0.50=12.25

    How do you transfer value returned by enter_hours to the calculateCharges?
    Where do you calculate Total?
    i really don't know as i quite new in function..

    i haven't do the part of total because i already encountered problems without doing the total part...

  7. #22
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    laserlight...

    aren't you going to help me out...???

    anyone..

    please generously help out as i'm still very weak in c programming...

    thanks...

  8. #23
    C++まいる!Cをこわせ!
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    People have daily lives, ya know. Be patient.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  9. #24
    Hurry Slowly vart's Avatar
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    yes.. i did use it.. w supposed to be hours input by user..
    it is used to calculate the charge..
    It is inputted INSIDE this function - why do you make it a parameter?
    please have a look at there and it may kind of explain most of the things you have asked..
    I do not need your explanation. YOU need this explanation to understand YOUR errors

    there are 3 cars to be included in the systems..
    So what number of cars is doing in this formula:
    Code:
    2.00+0.50*n;
    2.00 + (23.5-3)*0.50=12.25
    so for 23h 30 min you will charge 12$ 50 cents and for 24h - 10$? Don't you see some contradiction here?

    i really don't know as i quite new in function..
    In most cases you do something like
    Code:
    float hours = 4.5;
    float charge = calculate(hours);
    
    ....
    
    float calculate(float hours_parked)
    {
       if(hours_parked <= 3.0f) return 2.0f;
       if(...)
    ...
       return 10.0f;
    }
    So you firstly initialize a variable - in your case using
    hours = get_hours();
    call and only then pass it as a parameter to other function
    All problems in computer science can be solved by another level of indirection,
    except for the problem of too many layers of indirection.
    – David J. Wheeler

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