Rexx Programming/How to Rexx/if

The if conditional construct allows a /statement/ or /block/ of code to be conditionally executed based on the result of a boolean expression. The branch within the condition, only gets executed if the expression evaluates to a true value. The if condition its simplest form is:

if CONDITION then STATEMENT
For example: if guess = 6 then say "Wow! That was a lucky guess."

There is no endif cocomponent
Note that rexx programming language syntax does not utilize endif as a syntactical cocomponent. The endif placed in a comment in example below are for cosmetic purposes only for aiding indentation. These comments are ignored by the rexx interpreter.

if guess = 6 then say "Wow! That was a lucky guess." else say "Sorry! That was not the right number." /* endif */

Using the do construct to conditionally execute a branch containing more than one statement
In order to conditionally execute more than one statement within a conditional branch, it is necessary to enclose the statements within a do and end block:

if guess = 6 then do    say "Wow! That was a lucky guess." /* Multiple statements in a do block */ prize = 30000 end

Nested conditional constructs
It is possible to created nested if structures:

if age > 79 then say "Wow! You are so old that you are almost antique!" else if age >=65 then say "You are a pensioner" else if age > 21 then say "You have the key to the door" else say "You are just a youngster" /* endif */ /* endif */ /* endif */