Thread: Probably simple error - i am a newbie to the world of programming

  1. #1
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    Join Date
    Sep 2011
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    5

    Probably simple error - i am a newbie to the world of programming

    Why does it display a zero at the end?


    Code:
    #include "StdAfx.h"
    #include <stdio.h>
    #include <math.h>
    
    /* Function Prototypes */
    
    /*double	ffunction(),
    		dfunction(),
    		calcfunction(),
    		incguess(),
    		displayfound(),
    		displaynotfound();*/
    
    double ffunction(double beta, double gamma, double delta, double x, double fx);
    
    
    int
    main(void)
    {
    	double	b,
    		c,
    		d,
    		guess,
    			
    		ans=0;
    
    
    	printf("please enter b, c, d and guess>\n");
    	scanf("%lf %lf %lf %lf", &b, &c, &d, &guess);
    	ffunction(b,c,d,guess,ans);
    	printf("fx= %f\n", ans);
    	return(0);
    
    }
    double
    ffunction(double beta, double gamma, double delta, double x, double fx){
    	fx = (pow(x,3))+beta*pow(x,2)+gamma*x+delta;
    	return (fx);
    }

  2. #2
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    Jan 2009
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    1,485
    As far as I can tell you do nothing with the return value of ffunction(). fx inside ffunction is a local variable, it will not affect ans.

  3. #3
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    Read through Lesson 4: Functions. That should clear up most of your confusion. Additionally, you should set your compiler warnings to max and pay attention to them; that would have pointed out the problem for you.
    Quote Originally Posted by anduril462 View Post
    Now, please, for the love of all things good and holy, think about what you're doing! Don't just run around willy-nilly, coding like a drunk two-year-old....
    Quote Originally Posted by quzah View Post
    ..... Just don't be surprised when I say you aren't using standard C anymore, and as such,are off in your own little universe that I will completely disregard.
    Warning: Some or all of my posted code may be non-standard and as such should not be used and in no case looked at.

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