Question

Suppose an array is passed as a parameter to a method, and the method changes the first component of the array to 42. What effect does this have on the actual argument back in the calling program?

Answer 1

When an array is passed as a parameter to a method and the method changes the first component of the array to 42, this will have an effect on the actual argument back in the calling program. The original array in the calling program will also have its first component changed to 42.

Step-by-step explanation:

When an array is passed as a parameter to a method and the method changes the first component of the array to 42, this will have an effect on the actual argument back in the calling program. The original array in the calling program will also have its first component changed to 42.

This happens because arrays are passed by reference in Java. When the method modifies the first component of the array in the parameter, it is actually modifying the same memory location where the original array is stored. Therefore, any changes made to the parameter array will also affect the original array.

For example:

public class Main {
public static void main(String[] args) {
int[] array = {10, 20, 30};
modifyArray(array);
System.out.println(array[0]); // Prints 42
}

public static void modifyArray(int[] arr) {
arr[0] = 42;
}
}