Source
anchisholm
Hi All,
Hey i am not understanding the explanation given to the answer of this question. Can anybody explain it?
class A13 {}
class A14 {
public static void main(
String[] arg) {
A13[] a1 = new A13[1]; // 1
A13[][] a2 = new A13[2][1]; // 2
A13[][][] a3 = new A13[3][3][3]; // 3
System.out.print(a3[2][2][2]); // 4
a1[0] = new A13(); // 5
a2[0] = a2[1] = a1; // 6
a3[0] = a3[1] = a3[2] = a2; // 7
System.out.print(a3[2][2][2]); // 8
}}
What is the result of attempting to compile and run the program?
a. Prints: null
b. Prints: nullnull
c. Compile-time error at 1.
d. Compile-time error at 2.
e. Compile-time error at 3.
f. Compile-time error at 4.
g. Compile-time error at 5.
h. Compile-time error at 6.
i. Compile-time error at 7.
j. Compile-time error at 8.
k. Run-time error
Output: null and Run-time error explanation : The declaration A13[] a1 = new A13[1] declares a variable a1 that references an array that contains one component of type A13. The declaration A13[][] a2 = new A13[2][1] declares a variable a2 that references an array that contains two components of type A13[]. In other words, the array referenced by a2 contains two references to two subarrays of type A13[]. The size of each subarray is 1. The declaration A13[][][] a3 = new A13[3][3][3] declares a variable a3 that references an array that contains three components of type A13[][]. In other words, the array referenced by a3 contains three references to three subarrays of type A13[][]. The dimensions of the subarrays are 3 X 3. The dimensions of the array referenced by a3 are 3 X 3 X 3. The number of elements in the array referenced by a3 is 3 * 3 * 3 = 27 elements. Each of the three subarrays contains three components, where each is a reference to a subarray of type A13[]. Each of the 27 elements of the array referenced by a3 is a reference of type A13 that has been initialized to the default value of null. At line 7, a reference to the array referenced by a2 is assigned to each of the three components of the array referenced by a3, a3[0] = a3[1] = a3[2] = a2. Since the array referenced by a2 has dimensions 2 X 1, the array referenced by a3 now has dimensions 3 X 2 X 1. The number of elements is 6. An attempt to access any element beyond those 6 results in an exception at run-time.
