Choice I will cause the while loop to iterate while x is less than 6. The variable x is assigned 1 to start and then incremented by 2. It will be assigned the values 1, 3, 5 and then 7. When x has the value 7, the loop will terminate. The output will be 1 3 5. Choice II will cause the while loop to iterate as long as x is not equal to 6. The variable x is assigned 1 to start and then incremented by 2. It will be assigned 1, 3, 5, 7, ... and will cause an infinite loop as it will never equal 6. Choice III will cause the while loop to iterate while x is less than 7. The variable x is assigned 1 to start and then incremented by 2. It will be assigned the values 1, 3, 5 and then 7. When x has the value 7, the loop will terminate. The output will be 1, 3, 5.
The modulus operator (%) evaluates to the remainder when the first operand is divided by the second operand. For example, 2574 % 10 evaluates to 4 the remainder when 2574 is divided by 10. In the first iteration of the loop, result is assigned 0 10 + 2574 % 10 or 0 + 4 or 4. The value of num is updated to 257 since the division is integer division between two int values. In the second iteration, result is assigned 4 10 + 257 % 10 or 40 + 7 or 47 and num is assigned 25. In the third iteration, result is assigned 47 10 + 25 % 10 or 470 + 5 or 475 and num is assigned 2. In the fourth iteration, result is assigned 475 10 + 2 % 10 or 4750 + 2 or 4752 and num is assigned 0. At this point the loop will terminate and 4752 will be printed to the screen.
Since the books array has been declared of type Book, at compile time all objects stored in books are considered Book object regardless of their actual type. Therefore, any methods that are called on elements of books must be declared in Book. In order to call the pagesPerMinute() method on Book[0], we would need to use typecasting to let the compiler know that the object stored in the books array at this index is actually an AudioBook object.
The for loop control variable k starts with the value 3, is incremented by 1 and terminates the loop when its value is arr.length – 1. In the first iteration, when k is 3, arr[3] is assigned the value arr[4]. The contents of the arr have been updated to {1, 2, 3, 5, 5, 6, 7}. In the second iteration, when k is 4, arr[4] is assigned the value arr[5]. The contents of arr have been updated to {1, 2, 3, 5, 6, 6, 7}. In the third iteration, when k is 5, arr[5] is assigned the value arr[6]. The contents of arr have been updated to {1, 2, 3, 5, 6, 7, 7}. Then k is incremented to 6 and the loop terminates.
The value of the loop control variable k starts at 1 and is incremented by 2 as long as it is less than input.length. In this case, input is assigned “computer”, so input.length is 8. The values of k are 1, 3, 5, 7, and then when k is 9, the loop terminates. The statement input.substring (k, k + 1) will return the value of input at index k. The values that are added to output in order are “o”, “p”, “t”, and “r”. The value “optr” is returned.