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
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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.
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