LauanMafia LauanMafia - 4 months ago 16
C++ Question

Reading file into array of struct c++

I am trying to read a .txt file into an array of struct in this program and display the content.

The file looks like this:

Smith Jack 60 45 98
Harry Hisk 45 40 78
Kay Jacob 35.5 23 45
Dos hed 23 20 35
Noa Tom 55 12 32
Joe Peni 57 49 78
Vin San 25.6 23 65.5
Jes Dan 24.3 12 78
Zi Lee 56 49 99
Angi Dev 57 48 97
Donald David 60 50 96
Davis Lal 47 47 80
Alvis Sen 56 46 85
Jack Jill 45 45 75
Messy Lionel 60 49 100


The code I'm running:

#include <iostream>
#include <string>
#include <fstream>
using namespace std;
int main(){
const int SIZE=50;
int i;
struct Records {
string firstname;
string secondname;
float test1mark;
float midtestmark;
float annualmark;
}record[SIZE];

ifstream in("Data.txt");

if (!in){
cerr << "File can't be opened! " << endl;
system("PAUSE");
exit(1);
}
for (int i=0; i < SIZE; i++){
in >> record[i].firstname >> record[i].secondname
>>record[i].test1mark >> record[i].midtestmark >> record[i].annualmark ;
}
for (int i=0;i< SIZE;i++) {
cout << record[i].firstname<<" ";
cout << record[i].secondname<<" ";
cout << record[i].test1mark<<" ";
cout << record[i].midtestmark << " ";
cout << record[i].annualmark << " ";
}
return 0;
}


The output I'm getting:

Smith Jack 60 45 98
Harry Hisk 45 40 78
Kay Jacob 35.5 23 45
Dos hed 23 20 35
Noa Tom 55 12 32
Joe Peni 57 49 78
Vin San 25.6 23 65.5
Jes Dan 24.3 12 78
Zi Lee 56 49 99
Angi Dev 57 48 97
Donald David 60 50 96
Davis Lal 47 47 80
Alvis Sen 56 46 85
Jack Jill 45 45 75
Messy Lionel 60 49 100
nan 0 8.94237e-039
4.36192e-039 0 -2.3511e-038
0 0 -2.3511e-038
0 0 0
1.32253e-038 0 1.32251e-038
4.2039e-045 0 -2.11122e+037
1.32251e-038 0 3.21276e-039
1.4013e-045 0 -2.3511e-038
1.4013e-045 0 3.76158e-037
0 0 3.76158e-037
0 0 1.12104e-044
4.36195e-039 0 4.36194e-039
3.57331e-043 0 6.0615e-039
0 0 3.21276e-039
4.2039e-045 0 6.41272e-039
1.12104e-044 0 6.63812e-039
4.36205e-039 0 -2.75237e+038
0 0 6.59812e-039
6.63426e-039 0 1.4013e-045
0 0 6.47961e-039
3.21319e-039 0 3.21319e-039
6.59812e-039 0 3.21299e-039
8.40779e-045 2.24208e-044 6.01433e-039
6.6045e-039 0 2.54408e-029
0 0 6.6045e-039
0 0 6.43946e-039
5.88656e-039 0 -4.12495e+011
0 0 0
5.88656e-039 0 2.54408e-029
nan nan 6.43029e-039
0 0 0
5.93823e-039 0 -4.12495e+011
0 0 0
5.93823e-039 0 5.74532e-044
nan nan 5.93837e-039





Process exited after 0.05447 seconds with return value 0

Press any key to continue . . .

Can someone tell me what's wrong with it? I've tried using pointers but it just got worse. -Beginner

Answer

Your file has 15 lines, and so you can only read through 15 lines of data. You are using the variable SIZE to control how many lines should be read.

The problem is that SIZE is 50! It is not 15. When you are trying to read past the end of file, the input will not be read past the 16th line. So, the variables after index 15 will be uninitialized, which is undefined.

Either increase the amount of lines in your file to 50, or change SIZE to be 15.

Comments