structer and pointers c++

Question

how can i recall a file and calculate the data in that file

Answer 1

You need to be more specific about the records and data you are

trying to process. Here is how to open the file and read various data types.

You will probably have to declare a data type structure and store the records

in an array.

#include <stdio.h>

//suppose you have these variables

typedef struct _TDataRec

{

int x;

long longIntNum;

double dblAmt;

char str[25];

} *TDataRec;

struct _TDataRec array[N];

ReadFile(TDataRec A)

{

// opens the file

FILE * fptr = fopen("filename","r");

//reads the data

for (int iLoop=0; iLoop<N; iLoop++)

{

fscanf(fptr,"%d",&A[iLoop].x); // reads an integer value

fscanf(fptr,"%ld,&A[iLoop].longIntNum); // reads a long integer value

fscanf(fptr,"%lf",&A[iLoop].dblAmt); // reads a double value

fscanf(fptr,"%s",&A[iLoop].str); // reads string

// performs the calculations

//closes the file

fclose(fptr);

}