Thread: Conditional Statements

  1. #1
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    Conditional Statements

    I have some code and the user inputs the values for floating point variables a and b.
    I want to write an if statement whereby; if 'a' and 'b' are zero, then some code will be executed. If not, then move on. I'm not sure how to do this. I have tried already but it doesn't work! The code only gets executed when a is zero and is only depenedent on a
    can anyone please help

    Code:
    if(a == 0 && b == 0)
    	{
    	printf("\wrong!\n");
    	thank_you();
    	exit(1);
    	}
    thanks

    Stuart

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    Lightbulb

    thanks andrew. I know understand why its not working but im not sure as to the change I'm suppose to make to my code. How would I write:

    Code:
    if(a == 0 && b == 0)
    Thanks

    Stuart

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    ((a==0) && (b==0))
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    Question

    happy reaper

    i tried your suggestion but unfortunately is doesnt work. It is still only reliant on 'a' being zero and appears to be independent of 'b'

    Help please

  6. #6
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    you'll have to show more code. I see that as being fine.
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  7. #7
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    Oh, actually, I just checked your post. You may want to be careful with floating-point arithmetic.
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    Code:
    wrong(float a, float b)
    {
    	if((a == 0) && (b == 0))
    	{
    	printf("\nwrong\n");
    	thank_you();
    	exit(1);
    	}
    	return 0;
    }
    Is only dependent on value of 'a'. If a is zero, wrong will be displayed regardless of the value of b.

    thanks!
    Last edited by strokebow; 11-22-2006 at 08:18 AM.

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    Any ideas what I should do to overcome this hurdle?? It works when I change the varaiable and stuff to integers but I need them to be pointers. Can anyone please help!?!? Well and truely stuck!
    Last edited by strokebow; 11-22-2006 at 08:23 AM.

  10. #10
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    What are you sending to that function ?
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    Code:
    main()
    {
    	float a, b;
    
    statements;
    /* a and b are initialised here by user input*/
    
    wrong(a, b);
    
    etc
    
    }
    
    
    
    wrong(float a, float b)
    {
    	if(a == 0 && b == 0)
    	{
    	printf("\wrong\n");
    	thank_you();
    	exit(1);
    	}
    	return 0;
    }

    cheers!

  12. #12
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    You don't ever initialize your variables ?

    EDIT : Did you ever try printing out what the user gives you ? Also, main returns an int.
    Last edited by Happy_Reaper; 11-22-2006 at 09:00 AM.
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    yep, i tried printing out my variables and they print out exactly what i type in. Its the conditional code thats the problem because I changed all variables to integers and then the programme worked. What do you mean by main is int?

    Thanks 4 ur help

  14. #14
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    And one last thing, you can avoid the floating-point stuff by doing :
    ((a < 0.00001 || a > -0.000001) && (b < 0.00001 || b > -0.000001))

    Or something of the sort. But I've never encountered this type of problem before.
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  15. #15
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    Main returns an int. It should be int main(void) or something of the sort.

    Check this out : link.
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