Creating a solution > Using variables
 
Using variables
Variables provide a temporary location for storing data, which can then be accessed from any context in the file. You can declare variables in:
calculations using the Let function
scripts using the Set Variable script step and Insert script steps with a variable as the target
Variables are not available outside the file in which they are declared, and one user’s variables are not available to other users. If you need data to be available to other files or to multiple users, use a field (without global storage) instead of a variable.
When you declare a variable, you can specify its scope by adding a prefix before the variable name.
 
Scope
Prefix
Example
Availability
Let function
None
variablename
Only within the Let function where it is declared
local
$
$variablename
Only within the script where it is declared; cleared when the script ends
global
$$
$$variablename
Anywhere within the file where it is declared; cleared when the file is closed
Local and global variables (or even two local variables in different scripts) can have the same name but they are treated as different variables and can store different values.
You can use variables in:
calculations
scripts
file paths (see Creating file paths)
find requests that you create and edit in the Edit Find Request dialog box (see Specify Find Requests and Edit Find Request dialog boxes)
layouts as merge variables (see Inserting merge variables onto a layout)
Repetitions in variables
Variables can include an optional repetition number that appears in brackets [ ] immediately after the variable name. For example, the following returns 111:
Let ( [
$var[1] = 1;
$var[2] = 10;
$var[3] = 100
];
$var[1] + $var[2] + $var[3] )
Repetitions in variables are not supported in:
merge variables
file paths
find requests
Notes 
A variable name has the same naming restrictions as a field name. See About naming fields.
Variables are not supported in file paths that are stored in container fields.
The data type of a variable is determined dynamically based on the assigned data.
For more information on working with variables, see the FileMaker Knowledge Base.