Could not find or load main class java hello world

Question

I am trying to write hello world on java. My code is:

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

And when I run java youtube.java on cmd I got this error:

Error: Could not find or load main class youtube.java

how? I am just saving in notepad++ and then runing with cmd: **java youtube.java** — Aykhan Amiraslanli, Feb 01 '16 at 17:22
Reimeus I got this: 'javac' is not recognized as an internal or external command, operable program or batch file. — Aykhan Amiraslanli, Feb 01 '16 at 17:24
@DilaraAliyeva You need to have the JDK installed to compile applications. — Rabbit Guy, Feb 01 '16 at 17:28

score 0 · Answer 1 · answered Feb 01 '16 at 17:19

0

In Java the name of the public class has to be the same as the source file or you will get that error. Try changing the first line to class youtube.

answered Feb 01 '16 at 17:19

lanceg

86
6

Not worked :( `class youtube { public static void main(String[] args) { System.out.println("Hello World!"); } }` – Aykhan Amiraslanli Feb 01 '16 at 17:21
Yeah, try compiling it with `javac` as Abdelhak suggested. – lanceg Feb 01 '16 at 17:25
'javac' is not recognized as an internal or external command, operable program or batch file. – Aykhan Amiraslanli Feb 01 '16 at 17:25
You don't have the JDK (Java Development Kit) installed on your computer then. Without it, you won't be able to compile or run your java programs. See: http://www.oracle.com/technetwork/java/javase/downloads/index.html – lanceg Feb 01 '16 at 17:28
I have installed JDK – Aykhan Amiraslanli Feb 01 '16 at 17:30

Abdelhak · Accepted Answer · 2016-02-01T17:36:06.520

0

To compile the class java with cmd use:

  javac youtube.java

But if you want to run it use this:

  java youtube

If you have error with command javac check your Environment Variables.

edited Feb 01 '16 at 17:36

answered Feb 01 '16 at 17:24

Abdelhak

8,299
4
22
36

'javac' is not recognized as an internal or external command, operable program or batch file. – Aykhan Amiraslanli Feb 01 '16 at 17:25
@DilaraAliyeva try to Environment Variables like above – Abdelhak Feb 01 '16 at 17:29

score 0 · Answer 3 · answered Feb 01 '16 at 17:26

0

Here's what you need to do:

Assuming your file name is youtube.java,

Run the following:

javac youtube.java

Once it compiles, it should generate a myfirstjavaprog.class file.

To execute this class, you need to run the following command:

java myfirstjavaprog

Hope this helps!

answered Feb 01 '16 at 17:26

anacron

6,443
2
26
31

'javac' is not recognized as an internal or external command, operable program or batch file. – Aykhan Amiraslanli Feb 01 '16 at 17:26
You need to set JDK into your path variable in windows. – anacron Feb 01 '16 at 17:27
Go to Control Panel > System > Advanced > Environment variables. In that dialog, add your "C:\_PATH_TO_JDK\bin" to the `PATH` variable. – anacron Feb 01 '16 at 17:29

score 0 · Answer 4 · answered Feb 01 '16 at 17:52

0

Usually that issue is when you try to run application on older JRE, that is compiled with newer Java version. Check your java version, then compile code according to it. If you are using Eclipse, you can change that on configure build path option.

answered Feb 01 '16 at 17:52

Tarik Terzić

21
4

Could not find or load main class java hello world

4 Answers4