I can't get sprintf to work

[onlymx13]

I run code

//all required includes
char * floatToString (double f) {
char buffer[50];
sprintf(buffer,"%f",f);
return buffer;
}
void main() {
//everything necessary to set up gfx
double number = 25.25;
gfx_PrintStringXY(number, 50, 50);
}

and the screen gets messed up and the float doesn't print properly. Is this a mistake of mine?

[onlymx13]

Oops, I just realized this is old