Java array references and default initialization: determine f2[0] after assigning f2 = f1. public class ArrayTest { public static void main(String[] args) { float f1[], f2[]; f1 = new float[10]; f2 = f1; System.out.println("f2[0] = " + f2[0]); } }

Introduction / Context: This question is about Java array references, aliasing, and default values of primitive arrays. Java initializes arrays of primitives to their default values: 0 for numeric types, false for boolean, and \u0000 for char. Assigning one array reference to another creates an alias, not a copy.

Given Data / Assumptions:

• f1 is a new float[10], so all elements are initialized to 0.0f.
• f2 = f1 means f2 refers to the same array object as f1.
• No writes occur before reading f2[0].

Concept / Approach: Because f2 and f1 reference the same array, reading f2[0] is equivalent to reading f1[0], which is the default 0.0f for a newly allocated float array.

Step-by-Step Solution:

Verification / Alternative check: Writing f1[0] = 2.5f before printing would make f2[0] also 2.5 because of aliasing.

Why Other Options Are Wrong:

• NaN: Default is not NaN; NaN results from specific operations.
• Compile error: Assignment between compatible array references is legal.
• Garbage value: Java does not leave primitives uninitialized in arrays.
• Runtime exception: No out-of-bounds or null dereference occurs.

Common Pitfalls: Expecting C-like uninitialized memory or assuming f2 becomes a deep copy rather than an alias.

Final Answer: It prints f2[0] = 0.0