A number literal is a sequence of mostly digits consisting of one or more of the following characters: an integer, a decimal point, a fractional segment, an exponent indicator (“e” or “E”), and an optionally signed exponent value. These are all examples of literal numbers:
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It is possible to omit either the integer or fractional segment of a literal number, but not both. In addition, within the fractional segment, you can omit either the decimal point or the exponent value, but not both.
All number literals are internally converted to Institute of Electrical and Electronics Engineers (IEEE) 64-bit binary values. However, IEEE values can only represent a finite quantity of numbers, so certain values do not have a representation as a binary fraction. This is similar to the fact that certain values, such as 1/3, do not have a precise representation as a decimal fraction (the decimal value would need an infinite number of decimal places to be entirely accurate).
The values that do not have a binary fraction equivalent are generally number literals with more than 16 significant digits prior to their exponent. FormCalc rounds these values to the nearest representable IEEE 64-bit value in accordance with the IEEE standard. For example, the value:
123456789.012345678
123456789.01234567
99999999999999999
100000000000000000
This behavior can sometimes lead to surprising results. FormCalc provides a function, Round, which returns a given number rounded to a given number of decimal places. When the given number is exactly halfway between two representable numbers, it is rounded away from zero. That is, the number is rounded up if positive and down if negative. In the following example:
Round(0.124, 2)
returns 0.12,
Round(.125, 2)
returns 0.13.
Round(0.045, 2)
returns 0.05.
However, the IEEE 754 standard dictates that the number literal 0.045 be approximated to 0.0449999999999999. This approximation is closer to 0.04 than to 0.05. Therefore,
Round(0.045, 2)
returns 0.04.
IEEE 64-bit values support representations like NaN (not a number), +Inf (positive infinity), and -Inf (negative infinity). FormCalc does not support these, and expressions that evaluate to NaN, +Inf, or -Inf result in an error exception, which passes to the remainder of the expression.
“The cat jumped over the fence.”
“Number 15, Main street, California, U.S.A”
The string literal “” defines an empty sequence of text characters called the empty string.
“The message reads: “”Warning: Insufficient Memory”"”
All Unicode characters have an equivalent 6 character escape sequence consisting of \u followed by four hexadecimal digits. Within any literal string, it is possible to express any character, including control characters, using their equivalent Unicode escape sequence. For example:
“\u0047\u006f\u0066\u0069\u0073\u0068\u0021″
“\u000d” (carriage return)
“\u000a” (newline character)

Literals