Intermediate JavaScript

Overview Learning objectives What you'll learn Key facts Course syllabus FAQs What our customers say Get in touch

Course overview

This two-day Intermediate JavaScript course helps you move beyond standalone scripts and work more confidently with application-level code. You’ll focus on modern syntax, asynchronous programming and testing techniques, giving you a stronger foundation for building reliable JavaScript solutions. You’ll also develop the skills to make clearer development decisions and improve code quality and maintainability, enabling effective day-to-day delivery of JavaScript projects.

Advancing modern JavaScript development skills

This course is designed for developers who already understand JavaScript fundamentals and want to apply the language more effectively in professional software projects. You’ll learn how to organise code, handle complex behaviour and apply development practices that support long-term maintainability. It is particularly relevant if you looking to strengthen the way you approach JavaScript in delivery-focused environments and complex development work.

Learning objectives

Organise JavaScript code effectively
Work confidently with scope and closures
Apply object-based design principles
Use functional programming techniques
Manage asynchronous behaviour
Build modular JavaScript applications
Test JavaScript functionality

What you'll learn

You’ll explore how intermediate JavaScript techniques shape the way applications behave, grow and hold up under change. The course connects language features, code structure, asynchronous behaviour, tooling and tests to support more practical development decision-making. By the end, you’ll be better equipped to organise work, reduce avoidable complexity and build JavaScript that is easier for teams to support.

Scope, closures and structure

Strengthen your understanding of how JavaScript manages variables, functions and context. You’ll cover scope, lexical behaviour, the scope chain, closures and immediately invoked function expressions. This gives you a clearer view of how code behaves at runtime, helping you avoid hard-to-trace bugs and write JavaScript that other developers can follow, maintain and extend.

Object-oriented JavaScript

Develop a more structured approach to building JavaScript code using objects, classes, constructors, methods, inheritance, encapsulation and composition. You’ll look at when these techniques are useful and how they support reuse without making code unnecessarily complex. This helps you make better design choices when working on larger applications or shared codebases.

Asynchronous JavaScript

Learn how JavaScript handles tasks that do not run in a simple step-by-step order. You’ll examine the event loop, asynchronous callbacks, timers, Promises, async and await, and fetching data. This is particularly valuable when building responsive applications, working with external services or managing processes where timing, reliability and user experience all matter.

Testing JavaScript behaviour

Understand how testing helps protect quality as JavaScript applications become more complex during this Intermediate JavaScript. You’ll explore unit, integration and end-to-end testing, along with running tests, testing asynchronous code and using mocks. The emphasis is on building confidence in how your code behaves, so changes can be made with less risk and fewer regressions.

What’s included

Instructor-led training over two-days
Live virtual classroom environment
Hands-on exercises and live labs
All relevant course materials

Key facts

Certification

This course includes a completion certificate.

Who it’s for

This course is suitable for learners with existing JavaScript knowledge who want to develop more structured, scalable applications.

Prerequisites

You should be comfortable with JavaScript fundamentals, DOM manipulation and basic HTML/CSS.

Exam information

This course does not include an exam.

Optional extras

This course includes hands-on exercises and access to learning materials for continued practice.

Pre-course

No preparation work is required for this course.

Course syllabus

Dive into the detail of the course by looking at the syllabus below.

Day one

Session 1: Modern syntax, operators and data structures
- Destructuring
- Spread
- Rest parameters
- Short circuiting
- Logical assignment operators
- Enhanced object literals
- Optional chaining
- Nullish coalescing
- Sets and Maps

Day one

Session 2: Scope
- What is scope?
- Types of scope
- Lexical scope
- The scope chain
- Closures
- IIFEs

Day one

Session 3: Object-oriented programming
- What is object-oriented programming?
- Object templates
- Constructor functions
- The this keyword review
- Object prototypes
- Classes
- Fields, constructors and methods
- Static members
- Encapsulation
- Inheritance
- Composition
- Mutating arrays, including push and splice

Day one

Session 4: Functional programming
- Functions review
- What is functional programming?
- Pure functions
- Immutability
- Spread
- Functions as first-class objects
- Higher-order functions
- Callbacks
- Transforming arrays, including filter and map

Day two

Session 5: Asynchronous programming
- What is asynchronous programming?
- The Event Loop
- Asynchronous callbacks
- setTimeout and setInterval
- Promises
- async and await
- Reactive programming and observables
- Asynchronous programming and fetching data

Day two

Session 6: Modules, managed apps and tooling
- What is a module?
- Exporting and importing module features
- Embedding a module in HTML
- Default and named exports
- Aliases
- Module objects
- Modules, packages, libraries and frameworks
- Categories of tools
- Package management
- Module bundling
- Transpilation
- TypeScript
- Creating a managed app

Day two

Session 7: Testing
- The purpose of testing
- Types of testing
- Running tests
- Test tools
- Unit testing
- Integration testing
- End-to-end testing
- Testing asynchronous code
- Using mocks

FAQs

This course equips you with practical, intermediate-level JavaScript skills, including modern syntax, object-oriented design, async handling, and robust testing for scalable app development.

What level of JavaScript experience do I need?

You should already be comfortable with JavaScript fundamentals, DOM manipulation and basic HTML/CSS. This course is not designed as a first introduction to JavaScript. It is best suited to developers who can already write basic scripts and want to improve how they structure, test and maintain JavaScript in larger or more complex projects.

How will this course help my development work?

The course helps you make stronger decisions about how JavaScript code is organised and maintained. You’ll look at areas such as scope, closures, object-oriented design, functional techniques, asynchronous behaviour and testing. These skills support cleaner code, fewer avoidable defects and better confidence when working on applications that need to change over time.

Will the course cover asynchronous JavaScript?

Yes. You’ll explore how JavaScript handles asynchronous behaviour, including the event loop, callbacks, Promises, async and await, and fetching data. This helps you understand what is happening behind the scenes when applications manage timed tasks, external data or operations that should not block the user experience.

Does the course include testing?

Yes. Testing is covered as part of writing JavaScript that can be changed and supported with more confidence. You’ll look at unit, integration and end-to-end testing, along with testing asynchronous code and using mocks. The aim is to help you verify behaviour and reduce risk as applications become more complex.

Is this course useful for front-end and full-stack developers?

Yes, where your role involves writing or maintaining JavaScript. The course is relevant to developers who want to strengthen their approach to application structure, asynchronous behaviour, modular code and testing. It is particularly useful if you are moving beyond small scripts into more structured development work.

Will I receive a certificate?

Yes. The course includes a completion certificate. No formal exam is listed for this course, so the focus is on building practical JavaScript capability through instructor-led learning, examples and exercises.

What our customers say

“Good structure to course. Each technical aspect broken down by instructor and theory explained with practical examples, which aided understanding and provided guidance on best practice when applying in real life scenarios. Pace was good - fast enough to keep engaged, and not too overwhelming.”

Ross, Government

“John was very knowledgeable about the subject and clearly explained everything.”

Kimberley, Community Risk Reduction IT Systems - Fire

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