遇到个很奇怪的问题

#include<stdio.h>
#include<stdlib.h>
int main(void)
{
FILE * fp;
int i;
struct students{
char num[8];
int score;
}stud1[]={{"101",20},{"102",10},{"103",30},{"104",55},{"105",42}},stud2[5];
if((fp=fopen("file.bin","wb+"))==0){
printf("文件打开/创建失败！！");
exit(0);
}
for(i=0;i<5;++i)
fwrite(&stud1[i],sizeof(struct students),1,fp);
rewind (fp);
puts("学号 成绩：");
while(!feof(fp)){
fread(&stud2[i],sizeof(struct students),1,fp);
printf("%s %d\n",stud2[i].num,stud2[i].score);
}
fclose(fp);
return 0;
}
----------------------------------------------------------
while(!feof(fp)){
fread(&stud2[i],sizeof(struct students),1,fp);
printf("%s %d\n",stud2[i].num,stud2[i].score);
}
&stud2[i] 这里面的i是怎么递增的，没看到能让i递增的语句啊！！