Java "Hello World" program running issue

Question

I've trying to start learning Java and already in stuck with the easiest possible program (http://introcs.cs.princeton.edu/java/11hello/)

So I created HelloWorld.java with

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

Compiled it with D:\tmp\java>javac HelloWorld.java (all passed fine, without errors)

And tried to run compiled .class:

D:\tmp\java>java HelloWorld.class
Error: Could not find or load main class HelloWorld.class

I have

D:\tmp\java>javac -version
javac 1.7.0

and cannot get why such trivial example doesn't work :-S

Possible duplicate question (and has an accepted answer): http://stackoverflow.com/questions/3005433/java-problem-could-not-find-main-class-helloworld — Genzer, Aug 13 '11 at 03:46

score 7 · Accepted Answer · answered Aug 13 '11 at 03:45

7

You should run it as java HelloWorld (without .class extension).

answered Aug 13 '11 at 03:45

Crozin

43,890
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Ooops, shame on me. Thank you – zerkms Aug 13 '11 at 03:46

score 3 · Answer 2 · answered Aug 13 '11 at 03:45

3

Remove the .class when running the program.

java HelloWorld

Good luck on your coding journey!

answered Aug 13 '11 at 03:45

Perception

79,279
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Hehe, thanks ;-) I wish it will be smoothly than the start ;-) Btw, +1'd you but will check @Crozin, as long as he was faster, sorry – zerkms Aug 13 '11 at 03:54
1

Quick fingers get the sticky buns! – Perception Aug 13 '11 at 03:56

K.VENKATESAN · Answer 3 · 2012-06-15T05:56:18.587

many instance we forgot to close and reopen the command prompt after editing the environement varriable . 1. In the environement varriable -create system variable called JAVA_HOME set the JAVA_HOME value upto bin folder of your JAVA directory 'C:\Program Files\Java\jdk1.7.0_04\bin'.3.Edit path in the system variable and add ';%JAVA_HOME%'. 4. close the control panel and close the command prompt and reopen and compile and run.donot bother about class path.

you can test the functioning by typing javac

For the first time create file helloworld.java the folder c:\users\documents\helloworld.java in note pad and type the following

class helloworld 
{

public static void main(String [] args )
 {
System.out.println("Welcome Helloworld");
 }
}

after saving click command prompt and type

for compiling c:\users\documents\ javac helloworld.java

for running c:\users\documents\ java helloworld

Welcome to stackoverflow. This question was already answered over a year ago. Best to avoid reviving old threads unless the response adds something significant over all previous responses. — Leigh, Jun 15 '12 at 09:02

Java "Hello World" program running issue

3 Answers3

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