beginner
9 min read
Arrays and Objects Basics
A variable can hold one value—and that value can be a collection holding many related values. JavaScript arrays and objects are how you build those…
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Beginner articles
65 articles in this tag.
beginner
7 min read
Arrow Functions Basics
JavaScript arrow functions let you write the same functions you already know in fewer lines. The idea isn't new—only the syntax is shorter.
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beginner
9 min read
Basic Operators in JavaScript
You've learned how to store values in variables. Now it's time to make those values do something. JavaScript operators are the verbs of your code—they add,…
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beginner
10 min read
Build a Click Counter
There's a moment in learning JavaScript when things stop being abstract. You've studied variables and functions. You've followed along with examples. But…
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beginner
16 min read
Build a Digital Clock with JavaScript
There is a small magic moment in every beginner programmer's life: the first time a page changes itself, with no click, no refresh, no input from you. The…
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beginner
13 min read
Build a JavaScript Quiz App
You've learned arrays, conditionals, click events, and DOM updates as separate lessons. Now it's time to see them work together. A quiz app is the perfect…
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beginner
16 min read
Build a Modal Dialog with JavaScript
You have definitely seen a modal before. You clicked a button on a website, and a small window appeared on top of the page. Everything behind it went dark.…
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beginner
14 min read
Build a Number Guessing Game
You've clicked buttons. You've added items to a list. Now it's time to make JavaScript think.
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beginner
14 min read
Build a Searchable List with JavaScript
Every product you use has one: a search box that narrows a list as you type. Contact lists, product catalogs, dashboards, admin panels—they all use the…
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beginner
12 min read
Build a Simple Calculator
A calculator is not smart. It just remembers two numbers and one operator between clicks. Once you see that, the whole project becomes simple—and you will…
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beginner
14 min read
Build an Image Slider with JavaScript
An image slider looks like a piece of fancy UI magic. Underneath, it is just a number moving through an array and telling the page which image to show.…
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beginner
8 min read
Changing DOM Content
A static page is a finished product. A dynamic page is a conversation: the user clicks, submits, or types, and the page answers. That answer usually means…
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beginner
10 min read
Create a Random Quote Generator
Click a button. Watch the page change. That small moment—where your JavaScript stops just running and starts doing something visible—is the bridge between…
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beginner
8 min read
Creating and Removing Elements
A static HTML page is frozen the moment it loads. Real sites keep changing after that—a to-do item appears, a cart entry disappears, a new message slides…
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beginner
9 min read
Debug JavaScript with Browser DevTools Breakpoints
That is the worst kind of bug for a beginner, because the console gives you nothing to read. So you start adding console.log() lines, reloading, guessing,…
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beginner
9 min read
Fetch Data in the Browser with Loading, Success, and Error States
You click a button, the page freezes for two seconds, and then either fills in with data or stays empty forever. The code might be fine. The problem is…
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beginner
7 min read
Fix "Assignment to Constant Variable" in JavaScript
Now you're stuck on a question that feels bigger than the error itself: do you change the const to let, or do you rewrite the line that's failing? The…
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beginner
8 min read
Fix "Cannot Read Properties of null" in JavaScript
If you are new to JavaScript, this message can look like the browser is speaking a different language. It is not. It is telling you something simple: your…
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beginner
8 min read
Fix a JavaScript Event Listener That Is Not Working
You wrote the addEventListener line. You clicked the button. Nothing happened. No error message. No reaction. Just silence.
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beginner
9 min read
Function Parameters and Return Values
A function that always does the same thing is a dead end. A function that can accept input and hand back a result becomes a tool you can reuse anywhere.
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beginner
11 min read
Handle Delayed Project Results with JavaScript Promises and async/await
Your first projects probably felt instant. Click a button, the counter goes up. Type a task, it appears in the list. Every value was ready the moment you…
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beginner
9 min read
Handle Form Submissions with JavaScript
You fill out a form, hit submit, and the whole page jumps. Everything you typed is gone. The browser did what forms do by default: it sent the data and…
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beginner
7 min read
Handling Click Events
You have a button on your page. You want something to happen when someone clicks it. That moment—when a static page starts responding—is where JavaScript…
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beginner
8 min read
Introduction to Events
You built a button. It looks great. You click it, and... nothing. The page just sits there, politely ignoring you.
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beginner
7 min read
Introduction to Functions
Copying and pasting the same code over and over works for a while—until you need to change something and suddenly have to hunt through ten copies of the…
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beginner
12 min read
JavaScript Array Methods: map, filter, and reduce
You know how to build an array. Now comes the part where every beginner hits the same wall: you need to change the values, keep only some of them, or total…
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beginner
6 min read
JavaScript Closures: How Functions Remember Variables
A function can outlive the variables it was born next to. That sentence sounds wrong until you run it.
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beginner
9 min read
JavaScript Dates and Timestamps: Create, Inspect, and Understand Time
You type new Date() into the console and get back a long string with a time zone name you never asked for. You type Date.now() and get a big number. Same…
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beginner
11 min read
JavaScript Destructuring and Spread Syntax for Arrays and Objects
Three lines, three property reads, three variables. It works, and it is honest code. But then you see a modern codebase do the same job in one line, with…
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beginner
12 min read
Use JavaScript ES Modules in the Browser with import and export
The moment your script file gets long enough that you scroll to find a function, you have outgrown the single-file habit.
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beginner
8 min read
Using JavaScript in HTML Pages
A web page is three layers doing one job. HTML builds the structure, CSS styles it, and JavaScript makes it respond. This tutorial shows you how to add…
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beginner
10 min read
Work with JSON in JavaScript: Parse and Stringify Data
You log a value from an API or from localStorage, and it looks exactly like an object. You can see the keys. You can see the values. So you try to read a…
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beginner
8 min read
JavaScript Scope: Global, Function, and Block Scope
You write a variable inside a function, log it, and it prints perfectly. You move that same console.log two lines down, outside the function, and suddenly…
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beginner
9 min read
for Loops vs forEach vs map in JavaScript
You can loop over an array three different ways, and they all look nearly identical when you write them. So which one should you use?
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beginner
7 min read
null vs. undefined in JavaScript: Meaning and Common Sources
You log three things in the console. A variable you declared but never filled in. A property you hoped was on an object. A function call that was supposed…
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beginner
7 min read
JavaScript Object Methods and this: Use Data Inside a Method
You copy a method into a new variable, call it, and get undefined instead of the name you expected. Nothing in the object changed. Nothing in the function…
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beginner
9 min read
Recursion in JavaScript: Base Cases and Step-by-Step Tracing
That is the normal first experience with recursion. The function calls itself, the answer appears, and somewhere in the middle your mental model goes dark.…
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beginner
10 min read
JavaScript Regular Expressions: Match and Check Simple Text
You start with a simple check. Does this input contain a dash? You reach for includes(). Then the input changes shape, and suddenly you have five if…
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beginner
10 min read
JavaScript Set and Map: When to Use Each Collection
You have a list of tags with duplicates, or you want to count visits per user object, and your array or plain object starts fighting you. Here are the two…
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beginner
10 min read
Strict vs. Loose Equality in JavaScript: When to Use === and ==
Two equals signs and three equals signs look like a typo. They are not. They are two different questions, and one of them lies to you politely.
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beginner
10 min read
JavaScript String Methods Reference for Beginners
You have text in a variable. You want to check it, cut it, clean it, or change it. But which method does which—and what does each one give you back?
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beginner
8 min read
JavaScript Truthiness: Falsy Values and Conditional Checks
A condition does not ask whether a value is true. It asks what that value becomes when JavaScript forces it into a yes-or-no decision.
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beginner
9 min read
Handle JavaScript Errors with try, catch, and throw
One bad line can take down everything after it. Here is how to catch that failure at the exact point it happens, and how to throw your own when a function…
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beginner
8 min read
Keyboard and Form Events
A button click is one quick signal. Typing is a stream of signals. Every search box, sign-up form, and chat input depends on JavaScript watching that…
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beginner
9 min read
let, const, and var in JavaScript: Which Should You Use?
You already know how to declare a variable. You've probably written let score = 0 or const userName = "Alex" and moved on. But then you open an older…
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beginner
11 min read
Loops: for and while
Five console.log statements will print five numbers. Fifty will print fifty. Five hundred will print five hundred—if you have the patience to write them…
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beginner
12 min read
Make a Simple To-Do List
A to-do list is the first app where your page stops being a static document and starts remembering what the user does. Same event-listening idea as a click…
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beginner
8 min read
Making Decisions with if/else
Every program you write has to react to the world around it. A login form needs to say "Welcome back" to one person and "Invalid password" to another. A…
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beginner
11 min read
Model Application Data with JavaScript Objects
You have probably already written code like this: a cartTotal here, a userName there, an isLoggedIn flag somewhere else. It works, right up until you…
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beginner
8 min read
Modifying CSS with JavaScript
You already know how to select an element and change what it says. Now let's make it change what it looks like.
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beginner
10 min read
Next Steps in JavaScript
You finished the basics. You built a calculator, a to-do list, and maybe a number guessing game. The code runs. The buttons work. And now the map runs out.
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beginner
10 min read
Practical DOM Examples
You have learned how to select elements, change their content, update their styles, and create new elements from scratch. Each of those skills makes sense…
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beginner
10 min read
JavaScript DOM Manipulation Practice Exercises
You have read about getElementById, textContent, createElement, and remove(). You understand what they do on paper. But understanding a method and feeling…
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beginner
12 min read
JavaScript if/else and Boolean Practice Exercises
You can write an if/else statement. You know where the braces go and what console.log does. But when the condition gets even slightly tricky, you hesitate.…
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beginner
12 min read
JavaScript Function Practice Exercises
Reading about functions feels clear. Writing one from scratch feels different. That gap is normal—and it closes the same way for everyone: by running code,…
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beginner
10 min read
Read and Update URL Query Parameters with JavaScript
A query string is the page's small, shareable memory: the part of the address that survives a copy-paste, a bookmark, or a link sent to a friend. Here is…
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beginner
8 min read
Render an Array as a List in the DOM
You have an array of names sitting in your JavaScript file. You want those names to show up as bullet points on the page. The naive approach is to write…
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beginner
8 min read
Save Data in localStorage with JavaScript
You built something that works. A button that counts clicks. A form that collects a name. A little app that feels alive in the browser. Then you hit…
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beginner
10 min read
Selecting DOM Elements
You cannot change an element you cannot reach. Every update, style change, and click response on a web page starts with one act of finding. JavaScript…
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beginner
8 min read
textContent vs innerHTML in JavaScript
textContent treats your value as plain text. innerHTML treats it as HTML markup. Same string, two different outcomes—and one of them needs extra care when…
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beginner
11 min read
Toggle CSS Classes with JavaScript
You have a button. You have a menu. You want the button to hide the menu, and you want it to show the menu again when clicked a second time. If your first…
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beginner
11 min read
Variables and Data Types in JavaScript
Every program you will ever write starts with the same move: storing information so you can use it later. A user's name, a score, a shopping cart total, a…
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beginner
7 min read
What is the DOM?
Your HTML file is just text. It sits on disk, perfectly still, until a browser reads it. Yet the page you're looking at right now can change—text updates,…
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beginner
8 min read
Work with Multiple DOM Elements in JavaScript
You learned to select one button and make it respond to a click. Then your page grew five buttons that all need the same behavior—and your trusty…
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beginner
9 min read
Working with Strings in JavaScript
A website is mostly text doing work: a signup form checking an email address, a search bar cleaning up what a user typed, a dashboard greeting someone by…
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