Exam 70-483 topic 1 question 14 discussion

Actual exam question from Microsoft's 70-483

Question #: 14
Topic #: 1

You are developing an application that will convert data into multiple output formats.
The application includes the following code. (Line numbers are included for reference only.)

You are developing a code segment that will produce tab-delimited output. All output routines implement the following interface:

You need to minimize the completion time of the GetOutput() method.
Which code segment should you insert at line 06?

A. Option A
B. Option B
C. Option C
D. Option D

Show Suggested Answer

Suggested Answer: B 🗳️
A String object concatenation operation always creates a new object from the existing string and the new data.
A StringBuilder object maintains a buffer to accommodate the concatenation of new data. New data is appended to the buffer if room is available; otherwise, a new, larger buffer is allocated, data from the original buffer is copied to the new buffer, and the new data is then appended to the new buffer.
The performance of a concatenation operation for a String or StringBuilder object depends on the frequency of memory allocations. A String concatenation operation always allocates memory, whereas a StringBuilder concatenation operation allocates memory only if the StringBuilder object buffer is too small to accommodate the new data. Use the String class if you are concatenating a fixed number of String objects. In that case, the compiler may even combine individual concatenation operations into a single operation. Use a StringBuilder object if you are concatenating an arbitrary number of strings; for example, if you're using a loop to concatenate a random number of strings of user input.
References: http://msdn.microsoft.com/en-us/library/system.text.stringbuilder(v=vs.110).aspx

by robinnirola at April 20, 2020, 11:28 a.m.