Create a file and call it testdata3 The file should contain
Solution
// java programming solution
import java.io.BufferedReader;
import java.io.FileReader;
import java.math.BigInteger;
import java.util.StringTokenizer;
public class SumFromATextFile {
public static void main(String [] args ){
BigInteger sum = new BigInteger(\"0\");//for big size of data
//int sum = 0;
StringTokenizer data = new StringTokenizer(\" \");
try {
BufferedReader br = new BufferedReader(new FileReader(\"testdata3.txt\")); // read the file
String line = br.readLine(); // read the next line
while (line != null) {
data = new StringTokenizer(line,\" \");// number after space
while (data.hasMoreElements()) {
String s = data.nextToken();
if(s.matches(\"^(-?)\\\\d+$\")){
System.out.println(\"Num : \"+s);
sum = sum.add(new BigInteger(s));
//sum = sum + Integer.parseInt(s);
}
}
line = br.readLine();
}
System.out.println(\"Sum of the integer in the file is : \"+sum);
br.close();
}catch(Exception e){
System.out.println(\"File Not found Exception \");
}
}
}
// C Programming solution
#include <iostream.h>
#include <fstream.h>
#include<conio.h>
#include<process.h>
#include<math.h>
//using namespace std;
void main(void)
{ clrscr();
//input file name
char filename[] = \"testdata3.txt\";
ifstream inputfile;
int num;
int sum=0;
// opening input file for reading
inputfile.open(filename, ios::in);
// test if fail to open the file, do…
// error handling for file opening
if(inputfile.fail())
{
cout<<\"Opening file \"<<filename<<\" for reading\ \";
cout<<\"------------------------------------------\ \";
cout<<\"The file could not be opened!\ \";
cout<<\"Possible errors:\ \";
cout<<\"1. The file does not exist.\ \";
cout<<\"2. The path was not found.\ \";
exit(0); // 1-just exit
// 0-normal, non zero - some error
}
// if successful, do the following...
else
{
cout<<\"The \"<<filename<<\" file was opened successfully!\ \";
// declare some variables for simple calculation
// read data from input stream...
inputfile>>num;
// test, if end of file not found, do the following...
while(!inputfile.eof())
{
sum+=num;
// re-read the next item price within the loop
inputfile>>num;
}
cout<<\"The Sum is : \"<<sum<<endl;
cout<<\"\ -------DONE-------\ \"<<endl;
// close the input file
inputfile.close();
// test closing file, if fail to close the file, do...
// error handling for file closing
if(inputfile.fail())
{
cout<<\"The \"<<filename<<\" file could not be closed!\ \";
// something wrong, just exit...
exit(1);
}
// if successful close the file, do....
else
cout<<\"The \"<<filename<<\" file was closed successfully!\ \";
}
getch();
}

