各位好，我是一個剛接觸 java的新手 我的問題，詳細情形是這個樣子的 先手動建立一個外部檔案 xxx.txt，內容中，每一列有１個人名及其年齡 ex. AAA 24 BBB 23 CCC 28 DDD 26 EEE 28 然後，寫１個 java的程式，將這個外部檔案的內容讀入 並根據讀入的內容，輸出年紀最大的那筆資料到螢幕上 如果同時有２個人以上年齡相同，則隨機列出其中一個人 例如 CCC、EEE兩個人都是最大的２８歲，程式執行後隨機丟出 CCC或 EEE為結果 讀入外部檔案這部份我是會寫 不過後面的判別＆輸出就不大靈光了 QQ 因為我不知道要怎麼去分開處理同一行的名字和年齡 可以請高手幫我一下忙嗎？Thanks

目前我是這樣子寫 不過，跑出來的結果是錯誤的 沒辦法只單獨抓最大值列出來 會變成這樣子： The oldest person is AAA The oldest person is BBB The oldest person is CCC The oldest person is DDD The oldest person is EEE 現在還想不出來該怎麼改才對.... package chapt02; import java.io.*; import java.util.StringTokenizer; public class xxx { public static void main(String[] args) throws IOException { StringTokenizer tokenizer; String line, name, file="xxx.txt"; int age[] = new int[99]; try { FileReader fr = new FileReader("xxx.txt"); BufferedReader inFile = new BufferedReader(fr); line = inFile.readLine(); while(line != null) { tokenizer = new StringTokenizer(line); name = tokenizer.nextToken(); age = tokenizer.nextToken(); try { for(int i=1; i < a.length; i ) { a[i] = Integer.parseInt(age); } int max=0, maxVal = a[0]; for(int i=1; i < a.length; i ) { if (a[i] > maxVal) { max=i; maxVal=a[0]; } } System.out.println("The oldest person is " name); } catch (NumberFormatException exception) { System.out.println("Error in input. Line ignored:"); System.out.println(line); } line = inFile.readLine(); } inFile.close(); } catch (FileNotFoundException exception) { System.out.println("The file " file "was not found."); } catch (IOException exception) { System.out.println(exception); } } }

package chapt02;
import java.io.*;
import java.util.StringTokenizer;
public class xxx
{
    public static void main(String[] args) throws IOException
    {
        StringTokenizer tokenizer;
        String line, name, file="xxx.txt";
        int age[] = new int[99];            try
        {
            FileReader fr = new FileReader("xxx.txt");
            BufferedReader inFile = new BufferedReader(fr);
            line = inFile.readLine();
            while(line != null)
            {
                tokenizer = new StringTokenizer(line);
                name = tokenizer.nextToken();
                age  = tokenizer.nextToken();                    try
                {
                    for(int i=1; i < a.length; i  )
                    {
                        a[i] = Integer.parseInt(age);
                    }
                    int max=0, maxVal = a[0];
                    for(int i=1; i < a.length; i  )
                    {
                        if (a[i] > maxVal)
                        {
                            max=i;
                            maxVal=a[0];
                        }
                    }
                    System.out.println("The oldest person is "   name);
                }
                catch (NumberFormatException exception)
                {
                    System.out.println("Error in input. Line ignored:");
                    System.out.println(line);
                }
                line = inFile.readLine();
            }
            inFile.close();
        }
        catch (FileNotFoundException exception)
        {
            System.out.println("The file "   file   "was not found.");
        }
        catch (IOException exception)
        {
            System.out.println(exception);
        }
    }
}

我只是幫你加入code....... 這好像是站規吧...貼程式碼一定要有[co de]跟[/co de] 發表人 - Frances3399 於 2004/04/13 02:16:23

不太能理解你的程式結構說, 你只要一個一個讀進來, 然後一個一個跟目前最大值比不就好了. 裡面的 a[99] 有必要嘛? 把同一個age String 轉成 int 然後放到a[]陣列. 全部都是同一個值.......然後陣列全部相同的值再去跟最大值比......你只讀了一個啊  所以比一次就好囉.

import java.io.*;
import java.util.StringTokenizer;    public class Class {
    public static void main(String[] args) throws IOException {
        StringTokenizer tokenizer;
        String line,file="test.txt";
        String oldestMan="";
        int maxAge=-100;
        
        try {
            FileReader fr = new FileReader(file);
            BufferedReader inFile = new BufferedReader(fr);
            
            String name;
            int age;
            while( (line=inFile.readLine()) != null) {
                tokenizer = new StringTokenizer(line);
                name = tokenizer.nextToken();
                age = Integer.parseInt(tokenizer.nextToken());
                
                if (age > maxAge){
                    maxAge=age;
                    oldestMan=name;
                }
            }
            System.out.println("The oldest person is "   oldestMan " Age is " maxAge );
            inFile.close();
        }
        catch (FileNotFoundException exception) {
            System.out.println("The file "   file   "was not found.");
        }
        catch (NumberFormatException exception) {
            System.out.println("Error in input. Line ignored:");
        }
        catch (IOException exception) {
            System.out.println(exception);
        }
    }
}