如何正确编写此Objective C程序？

Question

需要一些帮助这个小编程..我只有3个错误..

:'(

**[

#include <stdio.h>
int main (void)
{
char A , B , C , D , E , F;
float id1[]; <<< *Definition of variable with array type needs an explicit size or an initializer*
float grade[]; <<< *Definition of variable with array type needs an explicit size or an initializer*
float marks[]; <<< *Definition of variable with array type needs an explicit size or an initializer*
float average;
float num1, kk=0;
/********* Jami, Abdulrahman *********/
printf("Enter The Student ID: ");
scanf("%d", &num1);
for (kk=0; kk<num1; kk++);
{
scanf("%d", &id1[kk]);
scanf("%d", &grade[kk]);
}
for (kk=0; kk<num1; kk++);
{
if (grade [kk]>85 &grade [kk]<=100);
A=A+1;

if (grade [kk]>70 &grade [kk]<85);
B=B+1;

if (grade [kk]>55 &grade [kk]<70);
C=C+1;

if (grade [kk]>40 &grade [kk]<55);
D=D+1;

if (grade [kk]>25 &grade [kk]<40);
E=E+1;

if (grade [kk]>=0 &grade [kk]<25);
F=F+1;
}
/********* Jami, Abdulrahman *********/
float aveerage;
float avrg, sum, lk;

sum = sum + marks[lk];
average = sum / num1;

for (lk=0; lk<num1; lk++);

return average;
}

]**

Answer 1

你必须给它一个像3的大小(它可以是任何整数)或其他东西:

例如:

float id1[];
//Should be:
float id1[3]; //Or whatever number you want.

或者你可以这样做:

float id1[] = { 0, 0, 0 }; //To get the same effect as id1[3] where they would all be initialized at zero.

甚至更好:

float id1[3] = { }; //Initialize all 3 elements to zero.