Language Guide

CHAPTER 6

Expressions

154 Variables

set myDoc to ref to document "Report" of application 

"Scriptable Text Editor"

set myDoc to ref document "Report" of application 

"Scriptable Text Editor"

After you create a reference with the A Reference To operator, you can use the

Contents property to get the value of the object that it refers to. The Contents

property is the value of the object speciﬁed by a reference. For example, the

result of the following expression is a string containing the text of document

Report of the Scriptable Text Editor.

contents of myDoc

Data Sharing 6

Data sharing allows you to create two or more variables that share the same

list, record, or script object data; it can be used to promote efﬁciency when

working with large data structures. Only data in lists, records, and script

objects can be shared; you cannot share other values. In addition, the shared

structures must all be on the same computer.

To create a variable that shares data with another variable whose value is a list,

record, or script object, use the Set command. For example, the second Set

command in the following example creates the variable yourList, which

shares data with the previously deﬁned variable myList.

set myList to { 1, 2, 3 }

set yourList to myList --this command creates yourList,

--which shares data with myList

set item 1 of myList to 4

get yourList --result:{ 4, 2, 3}

If you update myList by setting the value of its ﬁrst item to 4, then the value

of both myList and yourList is {4, 2, 3}. Rather than having multiple

copies of shared data, the same data belongs to multiple structures. When one

structure is updated, the other is automatically updated.