Programming instructions

Working with CFML expressions 23

Specifying quotation marks around values

When assigning literal values to variables, you must surround the literal value with

double quotation marks or single quotation marks. ColdFusion interprets the content

between the quotation marks as a literal value and assigns that value to the variable; for

example:

ColdFusion instantiates the variable my_first_name to the string literal Kaleigh.

Further,

Smith is assigned to the variable my_last_name and 5 is assigned to age.

When referencing a variable by its name, you do not surround the name with quotation

marks; for example:

<cfset the_string = "My name is " & variables.my_first_name &

" and my age is " & variables.my_age>

My name is

is literal text and, you therefore, surround it with quotation marks. The

variable references

variables.my_first_name and variables.my_age are not

surrounded by quotation marks. ColdFusion uses the values of the referenced variables

(

Kaleigh and 5, respectively) when assigning the value to the variable the_string.

To display quotation marks on a page as literal characters, you must double the quotation

marks; for example:

#mystring#

</cfoutput>

The result is the following output:

We all shouted "Happy Birthday" when he entered the room.

Specifying operators in expressions

In ColdFusion, you use operators to test conditions; for example, you use the

IS operator

to test for equality. When using operators in expressions, you must only use supported

logical operators that ColdFusion can interpret properly. For example, if you use the

greater than operator (>)or the less than operator (<), ColdFusion interprets these

operators as the start or end of a tag.

The following table lists the nonsupported logical operators and their equivalent

ColdFusion operators:

Nonsupported

logical operator

Equivalent ColdFusion decision

operator Description

= IS, EQUAL, EQ Tests for equality.

< LT, LESS THAN Tests for less than.

<= LTE, LE,

LESS THAN OR EQUAL TO

Tests for less than or equal to.