c++ - Functions using structure read from file return no output? -

i supposed declare structure holds name , grades of unknown number of students. here how did it:

struct student {     char name[30];     int grade1, grade2, grade3; }; 

then, have text file containing information each student on different lines. read way.

student info[20]; int nr_students,i=0,k=0; fstream infile; infile.open("in.txt"); fstream outfile; outfile.open("out.txt");  while(!eof) {     infile>>info[i].name;     infile>>info[i].grade1;     infile>>info[i].grade2;     infile>>info[i].grade3;     i++;  } nr_students=i; avg_promovability(outfile,info, nr_students); 

i not think works properly, since nr_students remains 0, apparently. also, first function:

void avg_promovability(fstream &outfile,student *info, int nr_students) {     int i;     float sum=0,j=0,avg;     (i=0;i<nr_students;i++)         if(info[i].grade1 >=5 && info[i].grade2>=5 && info[i].grade3>=5 ) {             sum=sum + info[i].grade1 + info[i].grade2 + info[i].grade3;             j++;         }     avg=sum/(3*j);     outfile<<avg;  } 

it's supposed calculate average grade of students have passed (that is, grades >=5). doesn't it, out.txt file empty. suggestions i'm doing wrong?

that not way check end of file. try

while (infile>>info[i].name) {      infile>>info[i].grade1;      infile>>info[i].grade2;      infile>>info[i].grade3;      i++; }