Java初學者：程序沒有編譯;收到錯誤消息

Question

我剛開始學習和使用Java。我試圖創建一個簡單的票程序：

import java.util.Scanner; 

public class First { 

public static void main(String[] args) { 
    String name; 
    int v_tickets, g_tickets; 
    double vip=1000.00, gen=500.00, total; 
    Scanner in=new Scanner(System.in); 
    System.out.printf("Enter your name"); 
    name = in.next(); 
    System.out.printf("How many VIP tickets do you want?"); 
    v_tickets = in.nextInt(); 
    System.out.printf("How many general Tickets do you want?"); 
    g_tickets = in.nextInt(); 
    total = (v_tickets*vip)+(g_tickets*gen); 
    System.out.printf("Receipt\n Name: %d\n %d VIP %6f\n %d General %6f\n Total %6f",name,v_tickets,v_tickets*vip,g_tickets,g_tickets*gen,total); 

} //end main 


} //end program 

但我不斷收到此錯誤信息：

--------------------Configuration: <Default>-------------------- 
Usage: java [-options] class [args...] 
     (to execute a class) 
    or java [-options] -jar jarfile [args...] 
     (to execute a jar file) 
where options include: 
-d32  use a 32-bit data model if available 
-d64  use a 64-bit data model if available 
-server to select the "server" VM 
-hotspot  is a synonym for the "server" VM [deprecated] 
       The default VM is server. 

-cp <class search path of directories and zip/jar files> 
-classpath <class search path of directories and zip/jar files> 
       A ; separated list of directories, JAR archives, 
       and ZIP archives to search for class files. 
-D<name>=<value> 
       set a system property 
-verbose:[class|gc|jni] 
       enable verbose output 
-version  print product version and exit 
-version:<value> 
       require the specified version to run 
-showversion print product version and continue 
-jre-restrict-search | -no-jre-restrict-search 
       include/exclude user private JREs in the version search 
-? -help  print this help message 
-X   print help on non-standard options 
-ea[:<packagename>...|:<classname>] 
-enableassertions[:<packagename>...|:<classname>] 
       enable assertions with specified granularity 
-da[:<packagename>...|:<classname>] 
-disableassertions[:<packagename>...|:<classname>] 
       disable assertions with specified granularity 
-esa | -enablesystemassertions 
       enable system assertions 
-dsa | -disablesystemassertions 
       disable system assertions 
-agentlib:<libname>[=<options>] 
       load native agent library <libname>, e.g. -agentlib:hprof 
       see also, -agentlib:jdwp=help and -agentlib:hprof=help 
-agentpath:<pathname>[=<options>] 
       load native agent library by full pathname 
-javaagent:<jarpath>[=<options>] 
       load Java programming language agent, see java.lang.instrument 
-splash:<imagepath> 
       show splash screen with specified image 
See http://www.oracle.com/technetwork/java/javase/documentation/index.html for more details. 

Process completed. 

我使用JCreator的，並在「生成輸出」它說：「過程已完成」，並沒有顯示我任何錯誤。但是上面的錯誤是我在'通用輸出'下得到的。任何幫助將不勝感激，請記住，我對此很新穎。

Answer 1

我沒有得到任何編譯錯誤。剛運行時異常

你printf格式錯誤

System.out.printf("Receipt\n Name: %d\n ...... , name...); 

name是一個字符串不是數字d

Receipt\n Name: %d\n 

應該

Receipt\n Name: %s\n 

的s是字符串

除此之外，程序運行對我罰款。之前我做了改變，我會得到

IllegalFormatConversionException: d != java.lang.String 

這是有道理的，因爲字符串不是數字

Answer 2

您正在顯示的java命令的用法。請執行以下操作：

1. 導航到您的First.java文件的存儲位置。
2. 類型javac First.java並回車。這將產生一個First.class文件。
3. 類型java First並回車。請注意，這裏沒有提到文件擴展名。

請不要考慮PeeSkillet的回答指出了需要對您的程序進行哪些更改。