Quick Coding Facts

Joanna

Got 30 seconds? Great — that’s all you need to learn something new!

Optional Chaining: The Safe Way to Access Data

You can avoid “Cannot read property of undefined” errors by using optional chaining, which safely checks whether a value exists before accessing its properties.

const city = user?.profile?.address?.city ?? "Unknown";

Optional chaining lets you navigate deeply nested objects without writing multiple defensive checks – clean, safe, and modern.

Did you know?

JavaScript

#Tip 019

Write Cleaner Code with Guard Clauses

Instead of writing nested if statements, you can use guard clauses – early-return checks that immediately stop the function when the input is invalid. This makes your code cleaner, easier to read, and much easier to maintain.

function processString(value) {
    if (typeof value !== 'string') return null;
    if (value.length <= 3) return null;

    return value.toUpperCase();
}

Did you know?

JavaScript

#Tip 018

Keep Only What You Need with .filter()

You can use .filter() to instantly remove unwanted items from an array while keeping the original array unchanged.

const positives = numbers.filter(n => n > 0);

.filter() returns a new array – perfect for cleanup, searches, and simple validations.

Did you know?

JavaScript

#Tip 017

Level Up Your Arrays with .map()

You can use .map() to instantly transform every item in an array into something new — without mutating the original one.

const labels = numbers.map(n => `Item: ${n}`);

.map() always returns a new array, making transformations clean and predictable.

Did you know?

JavaScript

#Tip 016

The Difference Between == and === in JavaScript

The loose equality operator == in JavaScript automatically converts values to the same type before comparing them.
This can cause unexpected results, so it’s usually better to use the strict equality operator ===

console.log(5 == "5");   
// true - because "5" is converted to a number

console.log(5 === "5");  
// false - because types are different (number vs string)

Did you know?

JavaScript

#Tip 011

Boost Scroll Performance with passive: true

Make scroll or touch listeners more performant – tell the browser you won’t call preventDefault()

window.addEventListener(
  'scroll',
  onScroll,
  { passive: true }
);

Did you know?

JavaScript

#Tip 010

Destructure and Keep the Rest

You can combine destructuring and rest syntax to extract what you need and keep the rest.

const { id, ...info } = { id: 1, name: "Alice", role: "Admin" };
console.log(info);      // { name: "Alice", role: "Admin" }

Did you know?

JavaScript

#Tip 009

Run an Event Listener Just Once

You can make an event listener run only once – it removes itself automatically after the first trigger.

button.addEventListener(
  'click',
  handler,
  { once: true }
);

Did you know?

JavaScript

#Tip 008

This collection of programming coding tips is a quick and easy way to learn something new – perfect for busy developers. No long explanations, no boring theory — just short, useful info in a “Did you know…” style.

You’ll find both basic things every programmer should know (at least in theory – but let’s be honest, our memory isn’t perfect and we often need Google or AI), and some funny or surprising facts that even experienced devs will enjoy.

Whether you’re just starting out, have been coding for years, or just like clicking on smart-looking stuff – there’s something here for you.

Get ready for a smile, a few “ah, now I get it!” moments, and maybe even a “good to know!”.

WARNING: Side effects may include sudden coding inspiration and a strong desire to share what you’ve learned with every developer around you.