Given the Visitor interface discussed in section 17.4 (shown below), select a statement to complete the class CodeFinder.The class is to be used when traversing a binary tree while displaying every data value that contains the code "007".
A)data.toString().indexOf("007") 0
B)data.equals("007")
C)data.toString().indexOf("007") = 0
D)data.contains("007")

Question

Given the Visitor interface discussed in section 17.4 (shown below), select a statement to complete the class CodeFinder.The class is to be used when traversing a binary tree while displaying every data value that contains the code "007".  
A)data.toString().indexOf("007") > 0 
B)data.equals("007") 
C)data.toString().indexOf("007") >= 0 
D)data.contains("007")

Quizplus · Accepted Answer

The indexOf() method returns -1 if the specified string is not found. Therefore, in order to ensure that all values containing "007" are captured, we should use the greater than or equal to operator (>=) instead of the greater than operator (>), which would exclude values at index 0. The contains() method is not available for strings in Java, so option D is incorrect. Option A would not correctly capture values at the beginning of the string, such as "007Agent", so it is also incorrect. Option B would only capture exact matches to the string "007", so it is too restrictive.

Given the Visitor Interface Discussed in Section 17