ColdFusion
has Five types of operators:
Arithmetic
Boolean
Decision (or comparison)
String
Ternary
Functions also can be viewed as operators because they act on
operands.
Arithmetic operatorsThe following table describes the arithmetic
operators:
Operator

Description

+  * /

Basic arithmetic: Addition, subtraction,
multiplication, and division.
In division, the right operand
cannot be zero.

++ 

Increment and decrement. Increase or decrease
the variable by one.
These operators can be used for preincrementing
or decrementing (as in x = ++ i), where the variable
is changed before it is used in the expression. They can also be
used for postincrementing or decrementing (as in x = i++),
where the value is changed after it is used in the expression. If
the value of the variable i is initially 7, for
example, the value of x in x = ++i is
8 after expression evaluation, but in x=i++, the
value of x is 7. In both cases, the value of i becomes
8.
These operators cannot be used with expressions that involve
functions, as in f().a++. Also, you can use an expression
such as ++x, but x and +++x cause
errors, because their meanings are ambiguous. You can use parentheses
to group the operators, as in (x) or +(++x),
however.

+= = *= /= %=

Compound assignment operators. The variable
on the right is used as both an element in the expression and the result
variable. Thus, the expression a += b is equivalent
to a = a +b.
An expression can have only
one compound assignment operator.

+ 

Unary arithmetic: Set the sign of a number.

MOD
or %

Modulus: Return the remainder after a number
is divided by a divisor. The result has the same sign as the divisor. The
value to the right of the operator should be an integer; using a
nonnumeric value causes an error, and if you specify a real number,
ColdFusion ignores the fractional part (for example, 11 MOD 4.7
is 3).

\

Integer division: Divide an integer by another
integer. The result is also an integer; for example, 9\4 is 2. The
right operand cannot be zero.

^

Exponentiation: Return the result of a number
raised to a power (exponent). Use the caret character (^) to separate
the number from the power; for example, 2^3 is 8. Real and negative
numbers are allowed for both the base and the exponent. However,
any expression that equates to an imaginary number, such 1^.5 results
in the string "1.#IND. ColdFusion does not support imaginary or
complex numbers.

Boolean operatorsBoolean,
or logical, operators perform logical connective and negation operations.
The operands of Boolean operators are Boolean (True/False) values.
The following table describes the Boolean operators:
Operator

Description

NOT
or !

Reverse the value of an argument. For example,
NOT True is False and the inverse.

AND
or &&

Return True if both arguments are True;
return False otherwise. For example, True AND True is True, but
True AND False is False.

OR
or 

Return True if any of the arguments is True;
return False otherwise. For example, True OR False is True, but
False OR False is False.

XOR

Exclusive or: Return True if one of the
values is True and the other is False. Return False if both arguments
are True or both are False. For example, True XOR True is False,
but True XOR False is True.

EQV

Equivalence: Return True if both operands
are True or both are False. The EQV operator is the opposite of
the XOR operator. For example, True EQV True is True, but True EQV
False is False.

IMP

Implication: The statement A IMP B is the
equivalent of the logical statement “If A Then B.” A IMP B is False
only if A is True and B is False. It is True in all other cases.

Decision operatorsThe ColdFusion decision, or comparison,
operators produce a Boolean True/False result. Many types of operation
have multiple equivalent operator forms. For example, IS and EQ
perform the same operation. The following table describes the decision
operators:
Operator

Description

IS
EQUAL
EQ

Perform a caseinsensitive comparison of
two values. Return True if the values are identical.

IS NOT
NOT EQUAL
NEQ

Opposite of IS. Perform a caseinsensitive
comparison of two values. Return True if the values are not identical.

CONTAINS

Return True if the value on the left contains
the value on the right.

DOES NOT CONTAIN

Opposite of CONTAINS. Return True if the
value on the left does not contain the value on the right.

GREATER THAN
GT

Return True if the value on the left is
greater than the value on the right.

LESS THAN
LT

Opposite of GREATER THAN. Return True if
the value on the left is smaller than the value on the right.

GREATER THAN OR EQUAL TO
GTE
GE

Return True if the value on the left is
greater than or equal to the value on the right.

LESS THAN OR EQUAL TO
LTE
LE

Return True if the value on the left is
less than or equal to the value on the right.

Note: In CFScript expressions only, you can also use
the following decision operators. You cannot use them in expressions
in tags. == (EQ), != (NEQ), > (GT), < (LT), >= (GTE), and
<= (LTE).
Decision operator rulesThe following rules apply to decision operators:
When ColdFusion evaluates an expression that contains
a decision operator other than CONTAINS or DOES NOT CONTAIN, it
first determines if the data can be converted to numeric values.
If they can be converted, it performs a numeric comparison on the
data. If they cannot be converted, it performs a string comparison.
This can sometimes result in unexpected results. For more information
on this behavior, see Evaluation and type conversion issues.
When ColdFusion evaluates an expression with CONTAINS or
DOES NOT CONTAIN it does a string comparison. The expression A CONTAINS
B evaluates to True if B is a substring of A. Therefore an expression
such as the following evaluates as True:
123.45 CONTAINS 3.4
When a ColdFusion decision operator compares strings, it
ignores the case. As a result, the following expression is True:
"a" IS "A"
When a ColdFusion decision operator compares strings, it
evaluates the strings from left to right, comparing the characters
in each position according to their sorting order. The first position
where the characters differ determines the relative values of the
strings. As a result, the following expressions are True:
"ab" LT "aba"
"abde" LT "ac"
String operatorsString
operators manipulate strings of characters. The following table
describes the operators:
Operator

Description

&

Concatenates strings.

&=

Compound concatenation. The variable on
the right is used as both an element in the concatenation operation
and the result variable. Thus, the expression a &= b is
equivalent to a = a & b.
An expression
can have only one compound assignment operator.

Note: In a Query of Queries, you use  as the concatenation
operator.
Ternary OperatorThe ternary operator is a decision operator with three
operands. It assigns a variable a value based on a Boolean expression.
The operator has the form
(Boolean expression)? expression1 : expresson2
If the Boolean expression evaluates to true,
the operator result is expression1; otherwise,
it is expression2
For example
<cfset c = (a GT b)? a : b >
If a is greater than b, c is
assigned the value of a; otherwise, c is
assigned the value of b.
The parentheses can contain any expression that evaluates to
a Boolean value, and a and b can
be any valid expression. You can nest this operator inside other expressions.


