IF Condition THEN
    statement(s)
{ ELSE
    statement(s) }
  ENDIF

Function
Evaluate Condition and, if it is true, run the code block that follows THEN, otherwise jump to the (optional) code block that follows ELSE. If no ELSE block is provided, the program will continue at the line that follows ENDIF.

• Condition  is a simple statement, such as "x = 7" that can be evaluated as True or False.
• Statement  is any valid SX/B program statement.

Explanation
IF...THEN...ELSE is a primary decision maker that allows one block of code or [optionally] another to run based on the result (True or False) of a condition. The available comparison operators are:

Comparisons are always written in the form: Variable Op Value.

• Variable  is a bit, byte or word variable.
• Op  is the comparison operator.
• Value  is a variable or constant for comparison.

This simple example shows how IF...THEN...ELSE is used with a subroutine that can accept a byte or word parameter.

' Use: DELAY ms
' -- 'ms' is delay in milliseconds, 1 - 65535

DELAY:
  IF __PARAMCNT = 1 THEN
    tmpW1 = __PARAM1                            ' save byte value
  ELSE
    tmpW1 = __WPARAM12                          ' save word value
  ENDIF
  PAUSE tmpW1
  RETURN

Related instruction: IF ... THEN