error: ‘y1’ redeclared as different kind of symbol

[oospill]

hello. I'm learning c, and made a program to calculate the distance between two points.. I got it to compile if my four input variables are xp1, yp1, xp2 and yp2. when I try to compile using x1,y1,x2,y2, I get the error: "error: ‘y1’ redeclared as different kind of symbol"

why can I use x1, but not y1?

thanks

[Dino]

You've done something wrong.

[RockyMarrone]

can u paste the code ??

[oospill]

#include <stdio.h>
#include <math.h>

char line[12];
float x1,x2,y1,y2;
float distance;
main()
{
        printf("Input X1 Y1: ");
        fgets(line, sizeof(line), stdin);
        sscanf(line, "%f %f", &x1, &y1);

        printf("Input X2 Y2: ");
        fgets(line, sizeof(line), stdin);
        sscanf(line, "%f %f", &x2, &y2);

        distance = sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));

        printf("Distance between points: %f\n", distance);

        return (0);
}

******
there's the code.. thanks to anyone for looking at this..

[slingerland3g]

You will need to call gcc with -lm

Past link on this same issue:
undefined reference to 'sqrt'

[Dino]

I pasted your code into my IDE (Xcode on a Mac) and I got the same error.

I then chose the "Preprocess" option and sure enough, y1 is already used in this context:

extern double y1 ( double );

So, it sucks that such a "common name" would already be defined. To fix, either pick some new variable names, or, change your variables to local variables by putting the declarations inside main() (they are Global now) to re-scope them.

[slingerland3g]

I pasted your code into my IDE (Xcode on a Mac) and I got the same error.

I then chose the "Preprocess" option and sure enough, y1 is already used in this context:

extern double y1 ( double );

So, it sucks that such a "common name" would already be defined. To fix, either pick some new variable names, or, change your variables to local variables by putting the declarations inside main() (they are Global now) to re-scope them.

Oh yes that too! That was strange.

[Dino]

I know - who would have thunk!