If you are a professional and you are working full time (sometimes even more), like yours trully, then here comes a good tip.
Not only once, but more often than I would like, I have answered wrongly a question just because I have read it fast.
Take a look at this question:
What is the output of the following?
if ($n > 0)
B) Parse Error: Syntax Error
At first you would consider A or E as the answer for this question, but, take a second look at the line where the function is defined. The function starts with 1, a number and in PHP you cant have functions names, variables names, class names, object names, etc, starting with numbers which make B the correct answer for this.