java的hasNext()的用法

Posted 2020-10-24 passion27

Java End-of-file

by Shafaet

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"In computing, End Of File (commonly abbreviated EOF) is a condition in a computer operating system where no more data can be read from a data source." — (Wikipedia: End-of-file)

The challenge here is to read  lines of input until you reach EOF, then number and print all  lines of content.

Hint: Java‘s Scanner.hasNext() method is helpful for this problem.

Input Format

Read some unknown  lines of input from stdin(System.in) until you reach EOF; each line of input contains a non-empty String.

Output Format

For each line, print the line number, followed by a single space, and then the line content received as input.

Sample Input

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

Sample Output

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

 

import java.util.*;
import java.io.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
class Main{
    
        public static void main(String[] args) {
           Scanner scan = new Scanner(System.in);
           for(int i = 1; scan.hasNext(); i++){
               System.out.println(i + " " + scan.nextLine());
           }
        }
       // sc.close();
        
    }