Question

A Consider the following method definition. The method printAllCharacters is intended to print out every character in str, starting with the character at index 0. public static void printAllCharacters (String str) for (int x = 0; x< str.length(); x++) // Line 3 System.out.print(str.substring(x, x + 1)); The following statement is found in the same class as the printAllCharacters method. printAllCharacters ("ABCDEFG"); Which choice best describes the difference, if any, in the behavior of this statement that will result from changing x < str.length() to x <= str.length() in line 3 of the method?
Α) The method call will print fewer characters than it did before the change because the loop will iterate fewer times.
B) The method call will print more characters than it did before the change because the loop will iterate more times.
C) The method call, which worked correctly before the change, will now cause a run-time error because it attempts to access a character at index 7 in a string whose last element is at index 6.
D) The method call, which worked correctly before the change, will now cause a run-time error because it attempts to access a character at index 8 in a string whose last element is at index 7.
E) The behavior of the code segment will remain unchanged.

Answer 1

Answer:

(c) The method call, which worked correctly before the change, will now cause a run-time error because it attempts to access a character at index 7 in a string whose last element is at index 6.

Explanation:

Given

printAllCharacters method and printAllCharacters("ABCDEFG");

Required

What happens when  x < str.length() is changed to x <= str.length()

First, we need to understand that str.length()  gets the length of string "ABCDEFG"

There are 7 characters in "ABCDEFG".

So: str.length()  = 7

The first character is at index 0 and the last is at index 6

Next, we need to simplify the loop:

for (int x = 0; x< str.length(); x++) means for (int x = 0; x< 7; x++)

The above loop will iterate from the character at the 0 index to the character at the 6th index

while

for (int x = 0; x<=str.length(); x++) means for (int x = 0; x<=7; x++)

The above loop will iterate from the character at the 0 index to the character at the 7th index

Because there is no character at the 7th index, the loop will return an error

Hence: (c) is correct