FORMULA LANGUAGE

Temporary variables
A temporary variable exists only within a formula. Its scope is that formula and it has no attributes other than the ones assigned to it within the formula.

The syntax for creating a temporary variable is:


The variable takes the type of the value on the righthand side of the equation. This value can be any of the field types or boolean. Boolean data types are returned by certain @functions and have a value of 1 (True) or 0 (False).

Using a variable name on the lefthand side of an equation results in a temporary variable unless preceded by the reserved word FIELD.

The following example makes extensive use of temporary variables to place the name of the current month in a field named MonthName. The steps are:

1. Place the current date in the temporary variable date.

2. Extract from date and convert to text month, the number of the month.

3. Create a text list "nMonths" with the values 1 through 12.

4. Create a text list "months" with the values January through December.

5. Replace the number value of the current month with its name.

date := @Created;
month := @Text(@Month(date));
nMonths := "1" : "2" : "3" : "4" : "5" : "6" : "7" : "8" : "9" : "10" : "11" : "12";
months := "January" : "February" : "March" : "April" : "May" : "June" : "July" : "August" : "September" : "October" : "November" : "December";
FIELD MonthName := @Replace(month; nMonths; months)

Variables can be assigned new values as a formula progresses.

Note Reassignment of a variable is new with Release 6. In previous releases, an attempt to reassign a variable resulted in an error.

The following example reassigns the temporary variable n at each iteration of an @While loop.

n := 1;
@While(n <= @Elements(Categories);
  @Prompt([OK]; "Category " + @Text(n); Categories[n]);
  n := n + 1

)

See Also