Program to add two integer numbers read from a text file and displaying results on console [closed]

Question

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.

Closed 8 years ago.

Even after lots of trial and error, I am unable to figure out how to write a java program that adds 2 integers (read from a text file) and displays addition result on the console.

I tried using FileInputStream, DataInputStream classes ...

Example explaining what I exactly need !

Suppose there are 2 integers stored in a text file (sample.txt) .... Let 1 and 2 be the integers.

I would like to read those integers from the file and display their sum (= 3) on the console

Any help would be appreciated !

P.S: I am a beginner in Java, so please be as simple as you can wrt coding !

Answer 1

Here's something you could start with:

import java.util.Scanner;
import java.io.*;

public class MyClass {

    public static void main(String[] args) throws IOException {

        Scanner s = new Scanner(new File("sample.txt"));
        int tmp1 = s.nextInt();
        int tmp2 = s.nextInt();
        System.out.println(tmp1 + tmp2);
    }
}

Create the text file directly under the Project root in Eclipse.

Sample content can be:

1 2

Answer 2

Your question isn't very clear at all, but providing you have the ints stored in a text file i.e

//sample.txt
1 2

You can use a Scanner to read the text file into an array of ints

Scanner scanner = new Scanner(new File("sample.txt"));

int [] numbers = new int [5];
int i = 0;
while(scanner.hasNextInt()){
   numbers[i++] = scanner.nextInt();
}

then print the result

int sum = 0;
for (int i = 0; i < numbers.size(); i++)
    sum += numbers[i];
System.out.println(sum);

(This will work for a text file of numbers up to 5 long) change "new int [5];" to have the number of elements you want as desired i.e new int [2];)

Hopefully this will be useful

Answer 3

Try this:

public static void main(String[] args) throws IOException {
    BufferedReader br = new BufferedReader(new FileReader("try.txt"));
    String line ="";
    int sum =0;
    while((line = br.readLine())!= null)
        sum = sum + Integer.parseInt(line);
    System.out.println(sum);
}

File try.txt:

1
2

Output:

3