Functions Reference

132 FileMaker Functions Reference
Data type returned
text, number, date, time, timestamp, container
Description
Sets varX to the result of expressionX for the duration of calculation, until the script
exits (local variables), or until the file is closed (global variables). Multiple variables are
allowed when using a list syntax that is enclosed in square brackets [ ] and is separated
by semicolons. For example:
Let([variable=value;variable2=value2];calculation)
The $ symbol references a local variable and two $$ symbols reference a global variable.
An optional repetition number appears in square brackets [ ] immediately after the variable
name. For example:
Let([$variable[repetition]=value;$$variable2=value2]{;calculation
} )
The Let function sets the variables from left to right. You can use previously defined
variables (for example, variables that you defined with the Set Variable script step) to
define new variable values, and you can nest one Let function within another. If you use
a previously defined variable within a nested Let function, the variable has scope only
within the nested function (as if you had defined a completely unique variable). See the
City example shown below.
Once defined, local and global variables can be referenced in any calculation within their
scope. The scope of global variables is limited to the current file. The scope of local
variables is the current script. Local variables defined in a calculation are scoped to the
file but are only available when scripts are not running. A local and global variable (or even
two local variables in different scripts) can have the same name but they are treated as
different variables and store different values.
Examples
Let(x=5;x*x) returns 25.
Let([x=5;squared=x*x;cubed=squared*x];cubed) returns 125.
Let(City=“Paris”;Let(City=“San Francisco”;City&“-“)&City) returns
San Francisco - Paris.
The following example sets a local variable counter at repetition 50 with a value of 120:
Let($counter[50]=120;$counter[50]*2) returns 240.
The following example shows how to pass named parameters using the Evaluate, Let,
and Get(ScriptParameter) functions, allowing access only to variable 'a' (the
example returns 6):
ScriptParameter = "a = 5; b = 10"
Evaluate("Let([" & Get(ScriptParameter) & "]; a+1 )" )