Tutorial Details:
Difficulty Level: Intermediate
Topics Covered: Using the If statement to make decisions.
Assumed Knowledge: The Basics, My First Program
Written By: BILL LANE

BACK

If you've ever programmmed in any other programming language then you will have probably encountered if. It is one of the most fundamental programming structure. Without it a program would be unable to respond to an event in a useful manner. So for those who've never seen if before let's have a look at it. If is all about asking a question and making a decision based on the answer. The main requirement is that the answer to the question can be either TRUE or FALSE. For example, we may have created a variable to keep track of the current score (gv_GameScore) and we'd like to test to see if the Spybot has achieved enough points to win. We would write something like this:

If (gv_GameScore == 6) /* command 1*/; /* command 2*/;

With commands being statements to execute if there are enough points. I have shown two commands here but there may be more. In place of == we could also have tested for < (less than), > (greater than) or <= (less than or equal to) or >= (greater than or equal to ) or != ( not equal to ). We could also use an optional else at the end of the if block to provide commands to execute if the the statement is false:

If (gv_GameScore == 6) /* command 1*/; else /* else command*/;

Therefore, in this case if the score isn't equal to 6 then the Else commands will be executed. That should be all you need to know about the if statement. It's simple enough. But it is a very powerful tool for making your missions more engaging.