ColdFusion Developer's Guide - Electromanuals.org

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My.Variable.With.Periods is: #My.Variable.With.Periods#
Request.Another.Variable.With.Periods is:
#Request.Another.Variable.With.Periods#
ADOBE COLDFUSION 8
ColdFusion Developer’s Guide
Creating Client and Cookie variables with periods
To create a Client or Cookie variable with a name that includes one or more periods, simply assign the variable a
value. For example, the following line creates a Cookie named User.Preferences.CreditCard:
Data type conversion
ColdFusion automatically converts between data types to satisfy the requirements of an expression’s operations,
including a function’s argument requirements. As a result, you generally don’t need to be concerned about compatibility
between data types and the conversions from one data type to another. However, understanding how
ColdFusion evaluates data values and converts data between types can help you prevent errors and create code more
effectively.
Operation-driven evaluation
Conventional programming languages enforce strict rules about mixing objects of different types in expressions. For
example, in a language such as C++ or Basic, the expression ("8" * 10) produces an error because the multiplication
operator requires two numerical operands and "8" is a string. When you program in such languages, you must
convert between data types to ensure error-free program execution. For example, the previous expression might have
to be written as (ToNumber("8") * 10).
In ColdFusion, however, the expression ("8" * 10) evaluates to the number 80 without generating an error. When
ColdFusion processes the multiplication operator, it automatically attempts to convert its operands to numbers.
Since "8" can be successfully converted to the number 8, the expression evaluates to 80.
ColdFusion processes expressions and functions in the following sequence:
1 For each operator in an expression, it determines the required operands. (For example, the multiplication
operator requires numeric operands and the CONTAINS operator requires string operands.)
For functions, it determines the type required for each function argument. (For example, the Min function
requires two numbers as arguments and the Len function requires a string.)
2 It evaluates all operands or function arguments.
3 It converts all operands or arguments whose types differ from the required type. If a conversion fails, it reports
an error.
Conversion between types
Although the expression evaluation mechanism in ColdFusion is very powerful, it cannot automatically convert all
data. For example, the expression "eight" * 10 produces an error because ColdFusion cannot convert the string
"eight" to the number 8. Therefore, you must understand the rules for conversion between data types.
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