public static void main(String[] args) — Each Keyword Explained

Direct Answer

In a traditional Java class, public static void main(String[] args) is the launcher entry method. public makes it accessible, static lets the launcher call it without an instance, void gives no return value, and the String array receives command-line arguments. The parameter name may differ and String... args is equivalent to String[] args.

Code Example

Here is a runnable program that uses the entry point exactly as the JVM expects, including reading a command-line argument so you can see what args is for.

public class Greeter {
    public static void main(String[] args) {
        String who = (args.length > 0) ? args[0] : "World";
        System.out.println("Hello, " + who + "!");
    }
}
// Run: java Greeter        -> Hello, World!
// Run: java Greeter Alice  -> Hello, Alice!

Notice args is just a normal String array — when you run java Greeter Alice, the launcher packs "Alice" into args[0], and with no arguments args is an empty array (never null). Everything the JVM needs to start is in that one method signature; the body is ordinary code.

Common Mistakes & Pitfalls

• Saying the JVM specification requires main for every Java program: the traditional java launcher uses this entry convention; other hosts and newer source forms can differ.
• Thinking the parameter must be named args: only the type matters.
• Thinking String... is different: varargs compiles to the same array parameter type.
• Expecting an overload to be selected: main(int) does not replace the supported entry signature.
• Returning an int from main: the traditional signature returns void; process status can be set through launcher/process mechanisms such as System.exit.