java 从文本文件中读取的两个整数相加并在控制台上显示结果的程序
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Program to add two integer numbers read from a text file and displaying results on console
提问by Salman
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.
即使经过大量的反复试验，我也无法弄清楚如何编写一个添加 2 个整数（从文本文件读取）并在控制台上显示加法结果的 Java 程序。
I tried using FileInputStream, DataInputStream classes ...
我尝试使用 FileInputStream、DataInputStream 类...
Example explaining what I exactly need !
示例解释了我到底需要什么！
Suppose there are 2 integers stored in a text file (sample.txt) .... Let 1 and 2 be the integers.
假设有 2 个整数存储在一个文本文件 (sample.txt) 中......让 1 和 2 为整数。
I would like to read those integers from the file and display their sum (= 3) on the console
我想从文件中读取这些整数并在控制台上显示它们的总和（= 3）
Any help would be appreciated !
任何帮助，将不胜感激 ！
P.S: I am a beginner in Java, so please be as simple as you can wrt coding !
PS：我是Java初学者，所以请尽可能简单地编写代码！
回答by Jops
Here's something you could start with:
您可以从以下方面着手：
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.
在 Eclipse 的项目根目录下直接创建文本文件。
Sample content can be:
示例内容可以是：
1 2
回答by rcbevans
Your question isn't very clear at all, but providing you have the ints stored in a text file i.e
您的问题根本不是很清楚，但是如果您将整数存储在文本文件中，即
//sample.txt
1 2
You can use a Scanner to read the text file into an array of ints
您可以使用扫描仪将文本文件读入一个整数数组
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
然后打印结果
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];)
（这适用于最长为 5 的数字文本文件）更改“new int [5];” 拥有所需的元素数量，即 new int [2];)
Hopefully this will be useful
希望这将是有用的
回答by Achintya Jha
Try this:
试试这个：
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:
文件try.txt：
1
2
Output:
输出：
3
