More about IF

IF statements are so simple and easy to use that there's not much more to say about them. But take a look at ``if2.f'' (or view it directly).

Run this program a few times to get a feel for how it works.

Here are several things that you should notice:

1. An IF statement can consists of more than one alternative. After the IF block, there can follow any number of ELSEIF blocks, followed by an ELSE block.

2. In any event, the entire IF statement always ends with exactly one ENDIF/@. Notice that there are no ENDIF statements in the middle.

3. The alternatives are considered from the top down. As soon as a condition is found that is true, the statements grouped with that alternative are executed and then control transfers to the end of the IF statement. If none of the alternatives are true, the statements in the ELSE block are executed.