| When calling a varargs method, you can either pass an explicit array of | |
| arguments, or individual arguments: | |
| ```java | |
| void f(Object... xs) { | |
| System.err.println(Arrays.deepToString(xs)); | |
| } | |
| ``` | |
| Both of the following print `[1, 2]`: | |
| ``` | |
| f(new Object[] {1, 2}) // prints "[1, 2]" | |
| f(1, 2) // prints "[1, 2]" | |
| ``` | |
| If the argument to the varargs method is a conditional expression, and either | |
| branch is not an array, the result of the expression will be implicitly wrapped | |
| in an array. | |
| ```java | |
| f(flag ? 1 : 2) // prints [1] or [2] | |
| ``` | |
| This means that if one branch is an array and the other branch is not, the array | |
| branch will become a multi-dimensional array: | |
| ```java | |
| f(flag ? new Object[] {1, 2} : 3); // prints [[1, 2]] or [3] | |
| ``` | |
| To avoid the implicit array creation, the other argument can be explicitly | |
| wrapped in an array: | |
| ```java | |
| f(flag ? new Object[] {1, 2} : new Object[] {3}); // prints [1, 2] or [3] | |
| ``` | |
| Or, if the multi-dimensional array was intentional, it can be written explicitly | |
| as: | |
| ```java | |
| f(flag ? new Object[][] {{1, 2}} : new Object[] {3}); // prints [[1, 2]] or [3] | |
| ``` |