JavaScript Developer

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

Course overview

This JavaScript Developer course develops the language knowledge and coding discipline needed to create structured, interactive web applications. Across four days, you’ll work with JavaScript syntax, browser-based behaviour, modular code and practical development patterns. The learning is designed to help you write clearer, more reliable code and apply JavaScript more effectively within day-to-day development, enhancement and maintenance work.

JavaScript skills for application developers

This four-day course is designed for technical professionals who want to build stronger JavaScript skills for practical development work. You’ll explore core language features, browser behaviour, code structure and testing, with a focus on writing clearer, easier-to-maintain solutions. It is suited to newer programmers, returning developers or those moving into JavaScript-based roles, as it helps you improve coding discipline and contribute more confidently to application delivery, enhancement and support.

Learning objectives

Write structured JavaScript code
Use variables and data types
Build reusable functions
Manage scope and programme flow
Manipulate browser page elements
Handle events and browser APIs
Apply object-oriented principles
Use functional techniques
Manage asynchronous code
Test application logic

What you’ll learn

Build stronger JavaScript development capability over this four-day JavaScript Developer course. With a focus on the skills that make the biggest difference in day-to-day coding, you’ll learn how JavaScript behaves when code runs, how to structure logic into reusable functions and objects, and how to organise and test code for improved maintainability. These skills help you move beyond syntax knowledge and write JavaScript that is clearer, more dependable and easier to adapt.

Understanding how JavaScript behaves

Explore how JavaScript runs, handles values and responds across different execution contexts. You’ll look at syntax, types, variables, objects and common sources of unexpected behaviour, giving you the insight needed to debug with more confidence. This matters because stronger code starts with knowing not just what to write, but why JavaScript behaves the way it does.

Writing clearer, reusable code

Build the skills that help you shape logic into functions, conditions, loops and object-based structures that are easier to follow and adapt. You’ll develop habits that help reduce repetition, improve readability and make changes less risky. These skills are important when code moves beyond isolated examples and needs to support real development work, maintenance and collaboration.

Choosing effective programming approaches

Compare object-oriented and functional techniques and how they support different types of coding problems. You’ll work with concepts such as classes, inheritance, composition, pure functions and immutability, learning how each approach can influence code structure. This helps you make more considered decisions when designing features or improving existing JavaScript.

Organising, testing and maintaining code

You’ll work with modules, asynchronous behaviour, tooling, TypeScript concepts and testing practices to manage JavaScript more effectively as projects grow during this course. You’ll learn how to organise code across files, handle delayed operations and check that JavaScript behaves as expected. Which is critical, as effective development is not just about getting code to run; it is about creating maintainable JavaScript that makes future changes and enhancements easier to make, review and trust.

What’s included

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

Key facts

Certification

This is a skills and knowledge-based course with no formal accreditation.

Who it’s for

This course is suitable for learners looking to develop or refresh their JavaScript skills and build modern web applications.

Prerequisites

A basic understanding of HTML, CSS, and programming principles are recommended before attending this course.

Exam information

This course does not include an exam.

Optional extras

This course includes hands-on labs 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: Introduction
- Setting up the development environment
- What is JavaScript?
- HTML and CSS refresher
- Embedding JavaScript in HTML
- Executing JavaScript with NodeJS
- Browser JavaScript vs NodeJS
- Simple example
- Syntax and comments
- ECMAScript and JavaScript
- Deployment

Day one

Session 2: Values, variables and types
- Values
- Variables
- var, let and const
- Naming conventions
- Numbers
- Strings
- Booleans
- Arrays
- Objects
- typeof operator
- Dynamic typing
- Type conversion and coercion
- Arithmetic
- Handling text, including template literals

Day one

Session 3: Functions
- Function declarations
- Parameters
- Return statements
- Function expressions
- Arrow functions
- Declaration, expression or arrow function?
- Calling functions
- Pass by value or reference
- Introduction to scope
- Default parameters
- Built-in functions

Day one

Session 4: Programme flow
- Relational and logical operators
- Equality comparisons and sameness
- Truthy and falsey values
- Conditional statements
- Iterative statements
- Error handling
- Debugging

Day two

Session 5: Objects
- Objects
- Properties
- Dot notation
- Square bracket notation
- Function properties and methods
- this keyword
- Iterating over object properties
- The Object type
- Array objects and methods
- String objects and methods

Day two

Session 6: DOM referencing and manipulation
- HTML elements and JavaScript objects
- The DOM
- DOM referencing
- DOM data types
- Element manipulation
- Creating, adding and removing elements

Day two

Session 7: Event handling
- Events
- Event propagation
- Event listeners
- Event listener registration
- The event object

Day two

Session 8: Web APIs
- What is an API?
- Browser APIs
- Accessing browser APIs
- Date
- Math
- RegExp
- JSON
- Client-side storage
- Geolocation
- Other Web APIs

Day three

Session 9: 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 three

Session 10: Scope
- What is scope?
- Types of scope
- Lexical scope
- Scope chain
- Closures
- IIFEs

Day three

Session 11: Object-oriented programming
- What is object-oriented programming?
- Object templates
- Constructor functions
- this keyword review
- Object prototypes
- Classes
- Fields, constructors and methods
- Static members
- Encapsulation
- Inheritance
- Composition
- Mutating arrays, such as push and splice

Day three

Session 12: Functional programming
- Functions review
- What is functional programming?
- Pure functions
- Immutability
- Spread
- Functions as first-class objects
- Higher-order functions
- Callbacks
- Transforming arrays, such as filter and map

Day four

Session 13: Asynchronous programming
- What is asynchronous programming?
- Event Loop
- Asynchronous callbacks
- setTimeout and setInterval
- Promises
- async and await
- Reactive programming and observables
- Asynchronous programming and fetching data

Day four

Session 14: 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 four

Session 15: Testing
- Purpose of testing
- Types of testing
- Running tests
- Test tools
- Unit testing
- Integration testing
- E2E testing
- Testing asynchronous code
- Using mocks

FAQs

This four-day JavaScript Developer course helps you strengthen how you write, structure, test and maintain JavaScript code. It covers language behaviour, reusable functions, objects, browser APIs, asynchronous programming, modules, tooling and testing, giving you practical skills for improving JavaScript used in day-to-day development work.

Is this course primarily about front-end development?

No. The course includes browser-based JavaScript, including DOM work, events and Web APIs, but it is not limited to front-end development. You’ll also explore at how JavaScript runs, how code is structured, how asynchronous behaviour works, and how modules, tooling, TypeScript concepts and testing support maintainable development.

What skills will I be able to apply after the course?

You’ll be better placed to write JavaScript that is clearer, more organised and easier to check. The course supports practical skills such as structuring logic, using functions and objects effectively, handling asynchronous operations, working with browser APIs, organising code across files and testing behaviour before changes are released or extended.

Is this course suitable if I already know some JavaScript?

Yes. It is suitable for learners who have some existing programming knowledge and want to strengthen or refresh their JavaScript capability. As well as covering syntax, the course also looks at how JavaScript behaves in practice and how you can use it more effectively when maintaining, improving or extending application code.

What should I know before attending?

Familiarity with HTML, CSS and basic programming concepts is recommended before attending. This helps you focus on JavaScript behaviour, coding approaches and development practices during the course, rather than spending the time getting comfortable with the wider web and programming basics.

How practical is the learning experience?

The course includes hands-on live labs, practical code examples, course materials and supporting resources. You’ll apply concepts as you learn them, which helps turn topics such as functions, objects, async programming, modules and testing into practical coding habits rather than abstract theory.

Will this help with maintaining existing JavaScript code?

Yes. The course is relevant if you need to improve, extend or maintain JavaScript code. You’ll work with areas that affect maintainability, including scope, functions, objects, modules, testing and asynchronous behaviour, helping you make changes with more confidence and reduce the risk of unexpected behaviour.

“Really informative course, structured to support all forms of learning and at a good pace.”

Owen, Graduate Trainee Engineer, Utilities

“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

Why study with TSG?

25+ years' experience

Trusted by individuals, businesses and public sector organisations for over 25 years.

20,000+ learners trained

Join a network of learners focused on developing their software testing skills

98% customer satisfaction

TSG trainers are frequently rated as ‘good’ or ‘excellent’ by our learners

Speak to our team

Guidance from experienced advisors

If you’re unsure which course aligns with your technical requirements or career direction, we’ll help you assess your options and choose with confidence.

Get in touch

Build capability

Develop skills that support real delivery outcomes

From software testing to broader digital skills, we work with you to design learning that strengthens capability, improves performance, and supports long-term business goals.

Get in touch