Conditionally executes the subsequent commands. If expression is nonzero, the If…[Then] command executes the subsequent commands until the next matching ElseIf, Else, or EndIf, are executed.
Syntax
If expression [ Then ]
The Then keyword is optional.
Example
'These two are functionally equivalent.
IF PLANE_ALT = 6000 THEN
PRINT "Aircraft altitude equals 6,000."
ENDIF
IF PLANE_ALT = 6000
PRINT "Aircraft altitude equals 6,000."
ENDIF