Question

What is the output of the following?

class ChangeIt
{
static void doIt( int[] z )
{
z[0] = z[ -1 ];
}
}

class TestIt
{
public static void main ( String[] args )
{
int[] myArray = {1, 2, 3, 4, 5} ;

ChangeIt.doIt( myArray );

for (int j=0; j System ( myArray[j] + " " ) ;
}
}

Answer 1

The output is an ArrayIndexOutOfBoundsException due to an attempt to access an invalid array index of -1.

Step-by-step explanation:

The output of the given Java code is an ArrayIndexOutOfBoundsException. In Java, array indexing starts from 0 and goes up to the length of the array minus one. Therefore, an index of -1 is invalid and not accessible in an array, resulting in this runtime exception. The ChangeIt class has a method named doIt, which tries to assign the value of the element at index -1 to index 0 of the array passed to it. However, since index -1 does not exist, the program will crash before it can reach the print statement within the TestIt class's main method.

The output of the given code is 5 2 3 4 5. Let's break down the code to understand how this is obtained.

The doIt method in the ChangeIt class takes an array as input and assigns the value at index -1 (which is the last index) to the first index of the array. In this case, it sets myArray[0] to myArray[-1], i.e., myArray[0] = 5.

Then, in the TestIt class, we call the doIt method with myArray as an argument. After that, we loop through the modified array and print its values. The loop starts at index 0, prints the value at that index, and continues until it reaches the length of the array. Thus, the output is 5 2 3 4 5.