Legal Ways to Declare and Initialize Arrays in Java

Quick Answer

Java gives two genuinely different ways to bring an array into existence, and recognizing both as legal (rather than assuming only one syntax is correct) is what this question is testing. Writing int[] arr = new int[3]; creates an array of a fixed size with every element set to its type's default value — zero for int — leaving the actual values to be assigned afterward. The alternative, int[] arr = new int[]{1,2,3};, skips specifying a size entirely and instead supplies the initializer list directly; the compiler infers the array's length from how many values appear inside the braces, and each element is populated with the given value immediately rather than a default. Both are legal, complete statements that declare and initialize an array in one line — they just serve different situations, one for when the size is known but values will be filled in later, the other for when the actual values are already known upfront. A shorthand form, int[] arr = {1,2,3};, is also legal but only at the point of declaration, not in a standalone assignment to an already-declared variable — a nuance worth knowing since it's a common source of a syntax error if used incorrectly.