Passing directly an array initializer to a method parameter doesn't work

Question

package arraypkg;

import java.util.Arrays;

public class Main
{
    private static void foo(Object o[])
    {
        System.out.printf(\"%s\", Arrays.toString(o));         


        

Answer 1

foo({1,2});

{1, 2} this kind of array initialization only work at the place you are declaring an array.. At other places, you have to create it using new keyword..

That is why: -

Object[] obj = {1, 2};

Was fine.. This is because, the type of array, is implied by the type of reference we use on LHS.. But, while we use it somewhere else, Compiler cannot find out the type (Like in your case)..

Try using : -

  foo(new Object[]{1,2});

Answer 2

foo({1,2}); doesn't tell what type of array it is. So, compiler fails to understand the syntax. All other declarations specify type of array.

Answer 3

foo({1,2}); is NOT an Array.

And as your foo() method takes an array type parameter, this fails.