“Could not find or load main class” Error while running java program using cmd prompt [duplicate]

Answer 1

One reason for this error might be

Could not find or load main class

Maybe you use your class name as different name and save the class name with another name you can save a java source file name by another name than class name. For example:

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

you can save as Hello.java but,

To Compile : javac Hello.java

This will auto generate A.class file at same location.

Now To Run        : java A