Get

Defining Getters in Object Literals

Creating getters directly in object literals is the most common and readable approach for defining accessor properties. The syntax uses the get keyword followed by the property name and a concise function body. This approach keeps the getter definition alongside other object properties, making the object's interface immediately visible to anyone reading the code.

Getters defined in object literals:

• Are own properties of the created object
• Are configurable and enumerable by default
• Do not require commas between them and other properties
• Execute their function body on every access

Computed Property Names with Getters

JavaScript allows dynamic computation of property names using bracket notation, and this capability extends to getters. By placing an expression in square brackets after the get keyword, you can create getter properties whose names are determined at runtime.

const prefix = "user";
const suffix = "Name";

const obj = {
 data: { admin: "Administrator", guest: "Visitor" },

 get [prefix + suffix]() {
 return this.data.admin;
 }
};

console.log(obj.userName); // "Administrator"

The computed property name allows the getter to be named dynamically based on the values of prefix and suffix. When the object is created, JavaScript evaluates the expression to produce the property name.

Getters in Classes

The get keyword works identically in class definitions, allowing you to define accessor properties on class instances. Class getters use the same syntax as object literal getters, but there are important distinctions in how they behave.

When building web applications with modern JavaScript frameworks, class-based getters provide an elegant way to expose computed properties that derive from instance data. The get keyword enables clean, readable APIs that feel like simple property access while encapsulating complex logic.

Instance Getters

Class getters are defined on the prototype and shared by all instances through the prototype chain, meaning the function objects are created once and shared among all instances. This is more memory-efficient than defining the same getters in each object literal.

class Rectangle {
 constructor(width, height) {
 this._width = width;
 this._height = height;
 }

 get area() {
 return this._width * this._height;
 }

 get perimeter() {
 return 2 * (this._width + this._height);
 }
}

const rect = new Rectangle(5, 10);
console.log(rect.area); // 50
console.log(rect.perimeter); // 30

Static Getters

Classes also support static getters, which are defined using the static keyword before the get keyword. Static getters define properties on the class constructor itself rather than on instances, making them useful for class-level utilities, constants, or factory methods.

class MathHelper {
 static get PI() {
 return Math.PI;
 }

 static get E() {
 return Math.E;
 }
}

console.log(MathHelper.PI); // 3.141592653589793

Key Differences from Object Literals

• Class getters are defined on the prototype and shared by all instances
• Class getters are not enumerable by default
• Static getters define properties on the constructor itself
• Comma separators between methods are not required in classes

These patterns are essential for writing clean, maintainable JavaScript functions and class-based code.

Adding Getters with Object.defineProperty()

While the get syntax in object literals is convenient, Object.defineProperty() provides low-level control for adding getters to existing objects or when you need precise control over property attributes.

Basic Usage

const obj = { a: 0 };

Object.defineProperty(obj, "computed", {
 get() {
 return this.a + 1;
 }
});

console.log(obj.computed); // 1

Descriptor Options

For accessor properties, the descriptor includes:

• get: Function called when property is read
• set: Function called when property is assigned (optional)
• enumerable: Whether property appears in iterations
• configurable: Whether property can be deleted or reconfigured

Backward Compatibility Pattern

One of the most valuable use cases for getters is maintaining backward compatibility when refactoring code. If you initially defined a property as a data property and later need to change its behavior or representation, you can add a getter to maintain the existing interface while changing the underlying implementation.

function User(name, birthday) {
 this.name = name;
 this.birthday = birthday;
}

let john = new User("John", new Date(1992, 6, 1));

// Later, add age as a computed property
Object.defineProperty(john, "age", {
 get() {
 const today = new Date();
 const birthYear = this.birthday.getFullYear();
 return today.getFullYear() - birthYear;
 }
});

console.log(john.age); // Computed based on birthday

This pattern is invaluable when APIs evolve but existing code cannot be immediately updated. By adding getters, new behavior can be introduced without breaking existing consumers. Combined with web development best practices, this approach ensures your code remains maintainable as requirements change.

Inspecting Network GET Requests with Chrome DevTools

While JavaScript's get keyword creates accessor properties, the concept of "get" also refers to HTTP GET requests. Chrome DevTools provides powerful capabilities for inspecting GET requests and understanding how browsers retrieve resources.

Accessing the Network Panel

1. Open Chrome DevTools (F12 or Cmd+Option+I on Mac)
2. Click the "Network" tab
3. Reload the page to capture requests

Key Features

• Request Recording: All network activity is recorded automatically
• Filtering: Type "method:GET" to filter for GET requests
• Request Details: Click any request to view headers, preview, response, and timing
• Timing Information: See breakdown of DNS lookup, connection, and download phases

Analyzing GET Requests

Each GET request shows:

• URL: The resource being requested
• Method: Should show "GET" for retrieval requests
• Status: HTTP response code (200 = success)
• Type: Content type (document, script, stylesheet, etc.)
• Size: Response body size
• Time: Total request duration

The Network panel is essential for debugging API calls, optimizing load performance, and identifying network issues in your web applications. Each request can be clicked to reveal detailed views with headers, response previews, and timing breakdowns.

Sources

1. MDN Web Docs: get
2. JavaScript.info: Property Getters and Setters
3. Chrome DevTools: Inspect Network Activity
4. BrowserStack: What is HTTP Request