Programming instructions

Working with CFML expressions 21

One of the tags that ColdFusion provides to display output is the cfoutput tag. The

cfoutput tag instructs ColdFusion to process all the code between the cfoutput start

and end tags. The syntax for the

cfoutput tag looks like this:

{normal html, text, and coldfusion processing instructions}

</cfoutput>

To return the value of a variable, you must always surround the variable name with

pound signs (#) and place the variable name between the

cfoutput start and end tags.

For example, the following code creates a variable and instructs the ColdFusion server to

return the value of the variable.

#variables.my_full_name#

</cfoutput>

The following is the output:

Kaleigh Smith

Working with CFML expressions

Expressions are an important part of the ColdFusion language. Expressions are a

collection of different elements, ColdFusion variables, functions, and operators. You can

think of them as strings of text that consist of one or more of the following elements:

• Literal text (string), numbers, dates, and other values

• Variables

• Functions

• Operators (& for joining statements, + for addition, and so on)

Many examples of expressions were shown in this chapter; for example:

• #variables.my_full_name#

• DateFormat(Now())

• my_first_name= "Kaleigh"

When you build expressions in ColdFusion, you can include simple and complex

elements; how you represent these elements determines how ColdFusion processes your

program.

Building expressions

In ColdFusion, you build expressions as you need them. The expressions can include

simple elements, such as the expressions shown previously, or they can include complex

elements, such as arithmetic functions, strings, and decision operators. (You build some

complex expressions in Part II of this book.)