c - 错误 : redeclaration of ‘y2’ with no linkage

Question

我正在尝试创建一个程序，该程序接收整数值并使用 atoi 将它们转换为 2 的补码整数，并确定进行了哪种类型的转弯。这是我的代码:

#include <stdio.h>
#include <stdlib.h>

int turn(int turn, int a1, int b1, int a2, int b2, int a3, int b3){
;
  turn = ((a1 * b1 + b1 * a3 + a2 * a3) - (b2 * a3 + a1 * b3 + a2 * b1));
  printf("\n value = %d \n", turn);

  return(turn);
}

int main( int argc, char *argv[] ) {

  int x1, y2, x2, y2, x3, y3, turn;

  x1 = atoi(argv[1]);
  y1 = atoi(argv[2]);
  x2 = atoi(argv[3]);
  y2 = atoi(argv[4]);
  x3 = atoi(argv[5]);
  y3 = atoi(argv[6]);

  turn = turn(x1, y1, x2, y2, x3, y3);

  if(turn == 0) printf("\n Straight \n");
  if(turn < 0) printf("\n Right Turn \n");
  if(turn > 0) printf("\n Left Turn \n");

  return 0 ;

}

还有我的错误:

make -k p3
cc     p3.c   -o p3
p3.c: In function ‘main’:
p3.c:29:19: error: redeclaration of ‘y2’ with no linkage
p3.c:29:11: note: previous declaration of ‘y2’ was here
p3.c:32:3: error: ‘y1’ undeclared (first use in this function)
p3.c:32:3: note: each undeclared identifier is reported only once for each function it appears in
p3.c:38:14: error: called object ‘turn’ is not a function
make: *** [p3] Error 1

编译在 9 月 22 日星期日 20:07:02 异常退出，代码为 2"

我想知道这个错误的原因。

谢谢，

Answer 1

您收到的错误正是消息告诉您的内容。

• 您声明变量 y2 两次
• 你没有在任何地方声明y1
• 您不能像这样有两个同名的成员。您有一个 turn 变量，它与您的 turn 函数同名。