C# Programming test problems

Question

I have just completed a C# practice test and have got some answers wrong, but I cannot get hold of my lecturer.

One of the questions that I didn't understand was "Which of the following is a common exception to the principle of naming variables with whole words?" The suggested answers are:

1. f
2. i
3. l
4. b

Why is the answer i?

Another question I don't understand is _"For which of the following lines of code will the following line be { the least often?". I didn't really understand this question because of the way it was written. The suggested answers are:

1. for (int i =0; i < myArray.Length; i++)
2. do
3. if (foundMatch)
4. }

The answer was }.

Answer 1

1. In C#, for loops are very common. When writing a for loop you need an index variable. By convention, the variable i is often used rather than the full word index. It is used so often, that most people understand that i is the loop index variable without having to think about it. There is no such convention (that I'm aware of anyway) for the other suggested variables, f, l and b. You would be better off spelling out what these variables represent in the code so that people understand it.

   Therefore the answer is i.

2. All of the statements for, do and if require a code block to follow them. The code block could either be a bare, single statement (less common) or a group of one or more statements surrounded by braces { and } (very common).

   For example:

   for (int i = 0; i < myArray.Length; i++)
   {
       ...
   }
   
   do
   {
       ...
   } while (!done);
   
   if (foundMatch)
   {
      ...
   }
   

   In contrast, the end of a code block } is almost never followed immediately by the start of another code block {. In other words, you won't see this in the code:

   if (foundMatch)
   {
       ...
   }
   {
       ...
   }
   

   Therefore, the answer is }.