Today I want to talk about the moment when programming actually started to "click" for me. It wasn't when I learned how to create a variable; it was when I learned how to structure them.
If you’ve followed my journey, you know that starting late means I didn't have years of computer science theory behind me. At first, variables were easy—boxes for storing single things. But I quickly realized that the real world is messy. In the applications I wanted to build (and the ones I work on now), you never deal with just one isolated value. You deal with collections.
I want to walk you through Objects and Arrays not just as syntax, but as the tools that finally helped me organize the chaos of data.
Arrays: More Than Just a List
Let's start with Arrays. When I first moved to Madrid, the Metro map looked like spaghetti to me. But eventually, I understood it as a sequence. Order is everything. You can't reach the third stop without passing the second.
In JavaScript, I learned to use square brackets [] to model this. It’s essentially a list where every item has a specific address, or index.
The hardest habit to break? Remembering that computers start counting at 0. "Line 1" is at index 0. It tripped me up constantly in the beginning. But once I grasped that, I realized arrays aren't just static lists; they are powerful tools we can interact with.
Manipulating Arrays
I rarely write code that just "sits there." In my early projects, I needed data that changed—shopping carts, to-do lists, user queues. I needed to add things and transform them.
I used to write long for loops to do math on lists of numbers, which was exhausting and prone to bugs. Then I discovered methods like push and the incredible map. It felt like unlocking a cheat code.
Notice map in that snippet. That function changed my career. It allowed me to transform data (like adding tax) without breaking or mutating the original list. In the React world I work in now, this is my bread and butter.
Objects: Describing the World
_Arrays _are great for lists, but I found them terrible for describing a person or a thing. I remember trying to store a user's data in an array like ['Carlos', 'Dev', 'Madrid'] and constantly forgetting which index held the city.
That’s when _Objects _clicked. They are for grouping related data using keys that actually make sense.
I love that details part. It shows that data can be nested. And see that bracket notation (user['role'])? I use that all the time when the key I need to access is coming dynamically from a database or an input field.
Reference Types vs. Primitives
This specific concept caused me more headaches than anything else. I used to stare at my screen, confused, asking: "If I declared this with const, why is _JavaScript _letting me change the contents?"
I had to learn that Arrays and Objects are Reference Types.
Think of the variable as a piece of paper with a home address written on it. The house (the data) can be renovated, furniture moved around, and walls painted. The address on the paper (the variable) hasn't changed, even though the house has. const protects the address, not the furniture inside.
This is a "gotcha" that catches almost every career switcher I know.
Modern Syntax: Spread and Destructuring
As I got more comfortable, I started caring about clean code. I didn't just want it to work; I wanted it to be readable. Modern _JavaScript _(ES6+) gave me tools that made my code look less like a manual and more like a sentence.
The Spread Operator (...)
I used to write complex functions just to merge two lists or copy an object. Now, the Spread operator does it for me. It looks like three little dots, but it does heavy lifting.
Destructuring
And then there is Destructuring. I got so tired of typing user.name, user.location, user.this, user.that. _Destructuring _lets me unpack what I need immediately. It makes the code feel lighter.
Putting It All Together: Arrays of Objects
Here is where theory finally met reality for me. When I started working with real APIs, I realized I wasn't just getting an Array or an Object. I was getting Arrays of Objects.
This structure a list of things, where each thing has details is the standard format for almost everything on the web, from social media feeds to product catalogs.
Mastering this wasn't overnight work. But understanding how to model data—whether I'm looking at a menu on Glovo or filtering events on Fever—is the skill that bridged the gap between "coding student" and "developer."
I hope sharing my mental model helps you see these structures more clearly! Open your console, break things, and fix them. See you in the next article.
This article was originally published on www.codesyllabus.com
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