== (equal), != (not equal), > (greater than), >= (greater than or equal to), < (less than), and <= (less than or equal to). You can also define the operators as abbreviations: EQ, NEQ, GT, GTE, LT, and LTE.true or false, so they're used in conditional statements, for example, IsArray which is true only when the variable is an "array". Structures have an instruction named structKeyExists() or keyExists() which returns true if a key is present in a structure. Strings can also be used for conditional operations by checking the .length() member function.if / else if / else expressions. Let's write an example by adding a method to our PersonalChef.cfc class:The water is not boiling yet..It's just barely boiling.It's boiling!.Hot! Hot! Hot!.if block has:if statement whose instructions are executed only if the statement is trueelse if statements whose instructions are executed only if the statement is trueelse statement whose instructions are executed if no if nor else if statements were trueif / else if / else structure can have its instructions run. If the if is true, for instance, CFML will never look at the else if. Once one block executes, that’s it.if, else, else if expression statements. It is very common in other languages and can be used for a more fluent expressive conditional expression.condition is evaluated. If it is true, then the true statement executed; if it is false, then the false statement executes.trueStatement and the falseStatement into more tenrary operations. However, don't abuse it as they will look ugly and just be very complex to debug.true of course!isDefined(), structKeyExists() and IF statements to do these kind of evaluations. They work, but not very expressive or concise.right default for a variable or an expression Or it is a short-hand way to do parameterization. It will allow us to set a value if the variable is Null or does not exist.userName does not exist or evaluates to null then the default value of the myName will be assigned the right part of the ?: elvis operator -> Anonymouskey not exists exception but returning an undefined or null value. You can then combine that with the elvis operator and create nice chainable struct navigation. For example instead of doing things like:?) along with the dot operator (.) is known as safe navigation operator(?.). The safe navigation operator makes sure that if the variable used before the operator is not defined or java null, then instead of throwing an error, the operator returns undefined for that particular access.switch / case / default block.if statement marks the start of an if block and contains one or more else if statements and perhaps one (and only one) else statement, the switch statement marks the start of a switch block and can contain multiple case statements and perhaps one (and only one) default statement.switch / case / default can only evaluate the resulting value of a single variable or expression, while the if / else if / else block lets you evaluate the true or false result of different variables or expressions throughout the block.case statements with curly braces. As best practice, do so for all case and/or default blockswhile( conditional ) expression allows you to execute a code block as many times as the conditional expression evaluates to true. This is a great way to work with queues, stacks or just simple evaluations.== and = Common Mistake= and ==.= is an assignment. It means "take what's on the right side and stick it into whatever is on the left side" (or its telling not asking.)== is a question. It means "is the thing on the right equal to the thing on the left" (or its asking not telling.)