Basic JavaScript is a beginner course in modern JavaScript, from variables, conditions, functions, arrays and objects to working with the DOM, handling events, validating forms and fetching data with the Fetch API. It suits complete beginners, people who already write HTML and CSS, and students, and you leave with a small working web app of your own.
JavaScript is the one language every browser understands, so it sits behind almost every button, menu, form and interactive screen on the web, and it is also the foundation of React, Vue, Node.js and many other modern tools. Yet many beginners learn from outdated examples that still rely on var, jQuery or browser features that are no longer recommended, which leads to buggy code and makes it hard to move on to newer tools.
This course starts from zero and teaches JavaScript the way it is written today. Learners set up VS Code and Chrome DevTools, then learn const and let, data types, operators, conditions, loops, functions, arrays and objects. They then apply all of this to real pages through the DOM and events, validate forms, fetch data from APIs with Fetch and async/await, store data with localStorage and split code into files with ES modules. The course closes with a workshop in which each learner builds a small, complete web app of their own. (2 days, 6 hours per day, 12 hours in total, Beginner level.)
Course Details
This course is the 2026 edition of the Basic JavaScript course. It runs for 2 days, 6 hours per day (12 hours in total, 09:00-16:00), as lectures alternating with labs. Beginner level, with no programming experience needed. This edition teaches JavaScript to the current ECMAScript standard, uses const and let instead of var, and drops outdated topics such as JScript, frames, the status bar, rollover effects and jQuery. It uses localStorage instead of cookies and adds the Fetch API, async/await and ES modules. It focuses on the foundations for beginners, unlike Advanced JavaScript, which goes on to classes, closures, the event loop, Node.js and testing. Learners take home a lab guide, starter files and solution code for every lab.
Section 1: Lab: Getting Started with JavaScript in the Browser
Section 2: Variables, Data Types and Operators
Section 3: Lab: Conditions and Loops
Section 4: Functions and Variable Scope
Section 5: Arrays, Objects and JSON
Section 6: Lab: Working with the Page Through the DOM
Section 7: Lab: Handling User Events
Section 8: Forms and Input Validation
Section 9: Lab: The Fetch API, async/await and Storing Data
Section 10: Workshop: Your Own List-Management Web App
No public rounds are open right now. Join the waiting list and we will contact you first when the next round opens, or ask us on LINE. Or call 02-570-8449 or 088-807-9770
The DOM (Document Object Model) is the tree of objects the browser builds from a page, which JavaScript can read and change. Select an element with document.querySelector(), change its text with textContent and its styling through classList, and create new elements with createElement() before adding them to the page with append(). Avoid putting user input straight into innerHTML, to prevent XSS.
var is the older way to declare variables: it is function-scoped and can be redeclared, which easily causes bugs. let is scoped to the block { } where it is declared and can be reassigned, while const is also block-scoped but cannot be reassigned. Modern code uses const by default and let when a value must change, such as a loop counter, and this course uses const and let throughout.
Select the button with document.querySelector(), attach a function to its click event with addEventListener('click', handler), and put the actions you want inside that function, such as changing text or showing and hiding a message. For forms, listen for the form's submit event and call event.preventDefault() so you can validate first, and use a real button element so it works with the keyboard.
It suits beginners who want to start programming with JavaScript, people who already write HTML and CSS and want interactive pages, students, developers from other languages and IT managers. No previous programming experience is required: you just need to be comfortable with a computer and a web browser. Some HTML and CSS will make it easier.
You will be able to write JavaScript with const and let, conditions, loops and functions, work with arrays, objects and JSON, control pages through the DOM and events, validate forms, fetch data from APIs with Fetch and async/await and store data with localStorage, with the workshop web app to show for it, ready to move on to Advanced JavaScript, React or Vue. Participants who complete the training receive a Certificate of Completion with its own number, which can be verified online.
Yes. It can be run in-house for your team, with examples adapted to your own work, such as adding form checks or data fetching to pages your team already looks after. You can request a quotation from this page, or contact us on LINE @itgenius or by phone on 02-570-8449.
Articles are published in Thai.
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