FormCalc supports a large set of built-in
functions with a wide range of capabilities. The names of the functions
are case-insensitive, but unlike keywords, FormCalc does not reserve
the names of the functions. This means that calculations on forms
with objects whose names coincide with the names of FormCalc functions
do not conflict.
Functions may or may not require some set of arguments to execute
and return a value. Many functions have arguments that are optional,
meaning it is up to you to decide if the argument is necessary for
the particular situation.
FormCalc evaluates all function arguments in order, beginning
with the lead argument. If an attempt is made to pass less than
the required number of arguments to a function, the function generates
an error exception.
Each function expects each argument in a particular format, either
as a number literal or string literal. If the value of an argument
does not match what a function expects, FormCalc converts the value.
For example:
Len(35)
The Len function
actually expects a literal string. In this case, FormCalc converts the
argument from the number 35 to the string “35”, and the function
evaluates to 2.
However, in the case of a string literal to number literal, the
conversion is not so simple. For example:
Abs("abc")
The Abs function
expects a number literal. FormCalc converts the value of all string
literals as 0. This can cause problems in functions where a 0 value
forces an error, such as in the case of the Apr function.
Some function arguments only require integral values; in such
cases, the passed arguments are always promoted to integers by truncating
the fractional part.
Here is a summary of the key properties of built-in functions:
Built-in function names are case-insensitive.
The built-in functions are predefined, but their names are
not reserved words. This means that the built-in function Max never
conflicts with an object, object property, or object method named
Max.
Many of the built-in functions have a mandatory number of
arguments, which can be followed by a optional number of arguments.
A few built-in functions, Avg, Count, Max, Min, Sum,
and Concat,
accept an indefinite number of arguments.
For a complete listing of all the FormCalc functions, see the Alphabetical Functions List.
