problem with a function

This is a discussion on problem with a function within the C Programming forums, part of the General Programming Boards category; Hi I am playing with functions for the first time [note, I am using C, not C++, so main ( ...

  1. #1
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    Question problem with a function

    Hi

    I am playing with functions for the first time [note, I am using C, not C++, so main ( ) is OK]. Here is my program:

    Code:
     	/* test for functions*/
    	
    	#include <stdio.h>
    	float FUNCTION;
    	main ( )
    	{
    		float xi, yi, x_new, y_new, h;	
    		xi = 1; yi = 1; h = 0.1;
    		y_new = yi + h * FUNCTION( xi, yi );
    		x_new = xi + h;
    		printf( "x\fy\n" );
    		printf( "%f\t%f\n", x_new, y_new );
    		}
    	}
    	float FUNCTION( float X, float Y )
    	{
    		return X + 3*Y/X;
    	}
    The compiler returns:

    line 12: Parse Error, expecting `','' or `SEP'
    'y_new = yi + h * FUNCTION( xi, yi )'
    aborting compile
    What is wrong? (Thanks)

  2. #2
    .........
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    Few things.

    Code:
    float FUNCTION;
    Instead of declaring a function prototype you are telling the compiler you want a floating point variable called FUNCTION. Try this
    Code:
    /* See how it matches your definition */
    float FUNCTION(float X, float Y);
    Also you really should return 0 and use int main (void). My compiler gives me warnings so it can't be a good thing. I'm pretty sure that main() isn't acceptable in c99 also. Another thing, althought it's a matter of style, usually names in all caps are used for defines. There was also an extra } in there. Goodluck.

  3. #3
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    Dear helper,

    I followed all your advice, and now my program compiles.

    Thank you.

  4. #4
    End Of Line Hammer's Avatar
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    Just a side note:

    >>I am using C, not C++, so main ( ) is OK<<
    http://faq.cprogramming.com/cgi-bin/...&id=1043284376
    When all else fails, read the instructions.
    If you're posting code, use code tags: [code] /* insert code here */ [/code]

  5. #5
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    I am happy that your program compiles.

    Just a little piece of advice,
    It is always good practice to use a return type,
    and have the function return a value.

    Stay away from void main()
    Indeed it is acceptable but ... think about
    return to VOID (?????????)

    I hope that this advice is good for you.

  6. #6
    ATH0 quzah's Avatar
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    Stay away from void main()
    Good so far...

    Indeed it is acceptable but
    Here's your problem. void main is not valid. A simple read of the FAQ would have answered this for you.
    5.1.2.2.3 Program Termination

    [#1]
    ...
    If the return type is not compatible with int, the termination status returned to the host enviornment is unspeficied.
    In short, if you want void man, use Java.

    Quzah.
    Hope is the first step on the road to disappointment.

  7. #7
    Toaster Zach L.'s Avatar
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    Correct me if I'm wrong, but doesn't C assume 'int' if no type is specified? So 'main ( )' is equivalent to 'int main ( )'.
    The word rap as it applies to music is the result of a peculiar phonological rule which has stripped the word of its initial voiceless velar stop.

  8. #8
    C++ Developer XSquared's Avatar
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    Read Hammer's link.
    Naturally I didn't feel inspired enough to read all the links for you, since I already slaved away for long hours under a blistering sun pressing the search button after typing four whole words! - Quzah

    You. Fetch me my copy of the Wall Street Journal. You two, fight to the death - Stewie

  9. #9
    Toaster Zach L.'s Avatar
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    I did... It didn't seem too clear on that point.

    edit: Never mind... I didn't see the word 'only'.
    The word rap as it applies to music is the result of a peculiar phonological rule which has stripped the word of its initial voiceless velar stop.

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