样本输入：

Question

在C ++中如果我想读取输入直到EOF，我可以按照以下方式进行操作

while(scanf("%d",&n))
{
    A[i]=n;
    i++;
}

然后我可以将此代码作为./a.out＆lt; input.txt中。这段代码的java等价物是什么？

Answer 1

你可以这样做：

Scanner s = new Scanner(System.in);
while (s.hasNextInt()) {
    A[i] = s.nextInt();
    i++;
}

Answer 2

// assuming that reader is an instance of java.io.BufferedReader
String line = null;
while ((line = reader.readLine()) != null) {
    // do something with every line, one at a time
}

如果您遇到困难，请告诉我。

Answer 3

 import java.io.BufferedReader;
 import java.io.FileReader;

BufferedReader br = null;  
     br = new BufferedReader(new FileReader(file));
       while ((line = br.readLine()) != null) {              

     }

    //using Scanner class

    Scanner scanner = new Scanner(file);
    while (scanner.hasNextLine()) {
      String line = scanner.nextLine();
      System.out.println(line);
   }

Answer 4

这是使用BufferedReader和FileReader类的Java等效代码。

  import java.io.BufferedReader;
  import java.io.FileReader;
  import java.io.IOException;

  public class SmallFileReader {
        public static void main(String[] args) throws IOException {
             BufferedReader br = new BufferedReader(new FileReader("Demo.txt"));
             String line=nul;
             while( (line=br.readLine()) != null) {
                    System.out.println(line);  
             }
  }
}

Answer 5

这是使用BufferedReader和FileReader类的Java等效代码。

  import java.io.BufferedReader;
  import java.io.FileReader;
  import java.io.IOException;

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

选项1：
                 String fileName = args[0];
                 BufferedReader br = new BufferedReader(new FileReader(fileName));
选项2：
                 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                 System.out.println("Enter a file name: ");
                 String fileName = br.readLine();

             //BufferedReader br = new BufferedReader(new FileReader("Demo.txt"));
             String line=null;
             while( (line=br.readLine()) != null) {
                    System.out.println(line);  
             }
  }
}

我对@Vallabh Code做了一些修改。 @tom如果要通过命令行输入文件名，可以使用第一个选项 java SmallFileReader Hello.txt
选项2将在您运行文件时询问您的文件名。

Answer 6

唯一对我有用的东西（你甚至不需要创建文件）

Scanner read = new Scanner(System.in);
String cadena;
boolean cond = true;
int i =0;
while (cond){
    cadena = read.nextLine();
    if(cadena.isEmpty())
        cond = false;
}

Answer 7

一个简单的解决方案是使用Scanner类。

请参见下面的摘录：

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

public class Solution {

    public static void main(String[] args) {

        Scanner s = new Scanner(System.in);
        while(s.hasNextLine())
        {
            String line = s.nextLine();
            System.out.println(line);
        }
    }
}

Answer 8

这是我的Java等效代码，用于读取输入，直到文件结束：

import java.util.Scanner;

public class EndOfFileSolutions {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        for(int i = 1; sc.hasNext()== true; i++){
            System.out.println(i + " " + sc.nextLine());
        }
    }
}

此代码将产生如下所示的输出-

样本输入：

Hello world
I am a file
Read me until end-of-file.

样本输出：

1 Hello world
2 I am a file
3 Read me until end-of-file.

此答案也可以很好地解决Hackerrank EOF problem

Answer 9

在Java中，读到EOF的一种方法是：-

     Scanner scan = new Scanner(System.in);    
     while(scan.hasNextLine())   //read until condition is true
     {
        String line = scan.nextLine();
        System.out.println(line);
        i++;
     }

Answer 10

Scanner scanner = new Scanner(System.in);
int c = 0;
while(scanner.hasNext()){
  System.out.println(++c + " " + scanner.nextLine());
}
scanner.close();
// use while instead of normal for loop. 
// If you need to read a file than BufferReader is the best way to do it, as explained above.

Answer 11

EOF 或行尾..！可以在单个 while 循环条件中实现.. !!，直到条件有效循环运行并从用户那里获取输入。“.hasNextLine”，正在检查是否有另一个输入行。例如，我正在使用 Hackerrank 练习。希望这对你有帮助。

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

public class Solution {

    public static void main(String[] args) {
        int i=1;
        Scanner sc = new Scanner(System.in); // Making Scanner object
        while(sc.hasNextLine()){            // This is the main condition for EOF  
            String line = sc.nextLine();
            System.out.format("%d %s\n",i,line);
            i++;
        } 
    
      
    }
}

在java中读取输入直到EOF

11 个答案:

样本输入：

样本输出：