Methods

A method is just a function that lives inside a CFC — everything from the Functions module (arguments, return values, scope) applies directly. The one new piece is that a method can read and modify the object's own properties without them being passed in as arguments.

Learning Objectives

After completing this lesson, you'll be able to:

Write a method that reads and modifies the object's own properties.
Call one method from another method on the same object.
Use the return-this pattern to enable method chaining.

A Method Using Its Own Object's Data

CFScript — ShoppingCart.cfc

component accessors="true" {

    property name="items" type="array";

    function init() {
        variables.items = [];
        return this;
    }

    function addItem(string name, numeric price) {
        arrayAppend(variables.items, {name: name, price: price});
    }

    function getTotal() {
        var total = 0;
        for (var item in variables.items) {
            total += item.price;
        }
        return total;
    }

}

Tag Syntax — ShoppingCart.cfc

<cfcomponent accessors="true">

    <cfproperty name="items" type="array">

    <cffunction name="init">
        <cfset variables.items = []>
        <cfreturn this>
    </cffunction>

    <cffunction name="addItem">
        <cfargument name="name" type="string" required="true">
        <cfargument name="price" type="numeric" required="true">
        <cfset arrayAppend(variables.items, {name: arguments.name, price: arguments.price})>
    </cffunction>

    <cffunction name="getTotal" returnType="numeric">
        <cfset var total = 0>
        <cfloop array="#variables.items#" index="item">
            <cfset total += item.price>
        </cfloop>
        <cfreturn total>
    </cffunction>

</cfcomponent>

NOTE

addItem and getTotal both operate on variables.items without it being passed in as an argument — that's the whole point of bundling data and behavior together.

Method Chaining: Returning this

A method that returns this (the current object) lets calls be chained together fluently, one after another, instead of writing a separate statement for each call.

CFScript

Simulated output — illustrative only, not a live ColdFusion/Lucee server.

Tag Syntax — User.cfc

Simulated output — illustrative only, not a live ColdFusion/Lucee server.

NOTE

Auto-generated setters from accessors="true" return void by default, not this — chainable setters like this have to be written by hand.

Common Beginner Mistakes

Trying to chain the auto-generated setX() methods

user.setName("x").setAge(1) fails because accessor-generated setters return void, not this. Write a custom method that ends in return this if chaining is needed.

Forgetting variables. when reading/writing an object's own property inside a method

Without the variables prefix, an unscoped assignment inside a method falls back to the VARIABLES scope, which happens to work by coincidence here — but explicitly writing variables.x makes the intent clear and avoids confusion with local (var) variables of the same name.

Best Practices

Explicitly scope a property access as variables.x inside a method, even though it isn't strictly required — it reads clearly and avoids ambiguity with local variables.
Use method chaining sparingly, for genuinely fluent APIs (like a query builder) — not every method needs to return this.

Interview Questions

What does a method need to return to support chaining?

this — the current object instance — so the next method in the chain can be called directly on the result.

Do accessor-generated setX() methods support chaining by default?

No — they return void by default. A custom method that explicitly returns this is needed for chaining.

Summary

In this lesson, you wrote methods that operate on their own object's properties, and covered the return-this pattern for method chaining.

What's Next?

The next lesson covers the constructor — the init() method, and the exact pseudo-constructor sequence that runs before it.