AppleScript in a Nutshell

Name

if [then] [else if] [else] end [if]

Syntax

If theBoolean then
   (* code statements *)
else if anotherBool then
   (* code statements *)
else
   (* code statements *)
end if

Description

The compound if statement can be used to test several boolean expressions and only execute subsequent script code if the enclosing expression is true. The syntax of the if compound statement is almost exactly the same as Visual Basic’s, JavaScript’s, and Perl’s, with some minor differences (for example, VB pushes the else and if together to make “elseif”). A plain-English pseudocode translation of this statement would be, “if this happens then run this code; else if that happens then run this code; else (if neither of the first two things happen) then run this default code.” You do not have to include any curly-brace characters ({ }) to enclose the conditional script code that the if statement contains. As long as you place different lines of code on separate lines, then the then part of if...then and the if part of end if are optional, as in the following code. The compiler puts the “thens” and “end if” in the right places.

Examples

In the following example, the (current date) ≥ date "1/1/2001" is the tested boolean expression. If it’s false, then the else statement(s) will execute.

Set yearCount to 0
if (current date) ≥ date "1/1/2001"  -- compiler will fill in 'then'
   display dialog "Welcome to 2001"
   set yearCount to yearCount + 1
else
   display dialog "Enjoy the end of 2000"
end -- 'if' is optional