[백준] #2557 : Hello World! - JAVA

문제 2557 : Hello World!를 출력하시오.

 

https://www.acmicpc.net/problem/2557

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풀어낸 답

public class test {
	public static void main(String args[]) {
		System.out.println("Hello World!");
	}
}

 

채점 결과

error: class test is public, should be declared in a file named test.java

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틀린 이유

error: class test(클래스명) is public, should be declared in a file named test(클래스명).java

클래스명이 public으로 선언되었는 데 파일명과 다를 경우

 

* 백준 문제 자바로 풀 때 유의사항

언어 도움말 페이지에 가면 java는 다음과 같이 컴파일/실행 한다고 되어 있다고 한다.

컴파일: javac -J-Xms1024m -J-Xmx1024m -J-Xss512m -encoding UTF-8 Main.java
실행: java -Xms1024m -Xmx1024m -Xss512m -Dfile.encoding=UTF-8 Main

 

따라서, class 이름은 반드시 Main 으로 해야 한다.

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방법1

/*
 * BaekJoon 2557
 * 2023.07.20
 * LEEHYERIN
 */
public class Main{
    public static void main(String args[]){
        System.out.println("Hello World!");
    }
}

 

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방법2

import java.io.BufferedWriter;
import java.io.OutputStreamWriter;
import java.io.IOException;
 
public class Main {
	public static void main(String[] args) throws IOException {
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
 
		bw.write("Hello World!");
		bw.flush();
		bw.close();
	}
}