如何在文件的同一行中添加两个数字

Question

Hello I need to add two integers in the same row of a file, separated by tab.

My file abc.txt has the following entry:

12  123
15  456

My program needs to add 12 with 123 and 15 with 456.

I am able to split the two entries in a row and convert them to integer, but I don't know how to treat them as separate numbers and add them.

For example, if I try to add then 12 adds with 12 and 123 adds with 123, where it should be 12+123.

Here is my program:

import java.io.*;
public class test {

    public static void main(String[] args) {
        String s = "";
        FileInputStream finp = null;
        InputStreamReader inpr = null;
        BufferedReader br = null; 

        try {
            finp = new FileInputStream(args[0]);
            inpr = new InputStreamReader(finp);
            br = new BufferedReader(inpr);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        try {
            while (true) {
                s = br.readLine();
                if (s == null)
                    break;

                for (int i = 0; i < 2; i++) {
                    String [] addrs = s.split("\t");
                    int a = Integer.parseInt(addrs[i]);
                    System.out.println(a + a);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

Bring your addrs variable out of the for loop, it is currently getting overwritten every iteration and you don't want that.

If your file will always have two numbers per row, you don't need a for-loop, you can just add them by using their indices:

String [] addrs = s.split("\t");
int a = Integer.parseInt(addrs[0]);
int b = Integer.parseInt(addrs[1]);
System.out.println(a + b);