Question

Does the parameter String args[] for accepting commandline arguments in main() have an impact if no commandline arguments are provided.

Does it:

1. Create a new object of String?
2. Is any memory allocated to it?

What does Java do when it encounters String args[]?

Update:
Wanted to ask a related a Question: If no cmdline args are provided, Will String args[] be empty or null?

Answer 1

A String[] is an object and an empty one will be about 16 bytes.

That was helpful. How can I calculate that myself?

public static long memoryUsed() {
    final Runtime rt = Runtime.getRuntime();
    return rt.totalMemory() - rt.freeMemory();
}

public static void main(String... args) {
    long before = memoryUsed();
    String[] arr = { };
    long after = memoryUsed();
    if(before == after) throw new AssertionError("you need to turn off the TLAB with -XX:-UseTLAB");
    System.out.printf("The String[] used %,d bytes of memory%n", (after - before));
}

prints

The String[] used 16 bytes of memory

Note: this print how much memory was used to create an object. This can be more than the amount retained if temporary objects are created.