DEV Community: Pixel and Code

Operators and Expressions (Programing Fundamentals Part — 3)

Pixel and Code — Sat, 02 May 2026 15:47:25 +0000

Hey, everybody welcome to the 3rd part of this series. Learning fundamentals of programming like a 5 years old, before learning any programming language.

Operators

Operators are special symbols that perform operations on variables and values, while expressions are combinations of variables, values, and operators that produce new results.

Let's understand more clearly. Basically, mathematical operations like addition, subtraction, division, and finding the remainder are represented by specific symbols. These symbols are used in programming so that the computer understands which mathematical operation to perform.

Addition: Represented by +
Subtraction: Represented by -
Division: Represented by /
Remainder (modulo): Represented by % (this will output the remainder after division)

Now let's see them in action:

int a = 2, b = 4, c = 0; //you can declare 3 variables together like this

c = a+b; //this will output 6, because 2+4=6
c = b-a; //this will output 2, because 4-2=2
c = b/a; //this will output 2, because 4 divided by 2 = 2
c = b%a; //this will output 0, because the remainder when dividing 4 by 2 is 0 (since 4 is perfectly divisible by 2)

Expressions

Expressions are combinations like a + b, b - a, Ext.

Data Types (Programing Fundamentals Part — 2)

Pixel and Code — Sun, 07 Sep 2025 06:42:01 +0000

This tutorial is part of a series I created to teach beginners the basic fundamentals of programming before diving into any specific programming language. If you're a beginner, you might want to start with the first part, but it's entirely up to you. Professionals are also welcome to read it and share any feedback on mistakes or unanswered questions, and it would be greatly appreciated if they could help address any incorrect or missing answers in the comments.

https://dev.to/pixelandcode/do-not-start-to-learn-programming-before-this-programming-fundamentals-part-1-4a0n

In previous blog we talked about variables. Now let’s talk about data types and I will teach while assuming that you are 5 years old.

Data Types

Before understanding them, its better know about some basic datatypes. May be some people will get it as soon as reading the types.

int (it is used to store whole numbers like 5,0,-3,22)

//int example
int car = 5;

float (Used to store numbers with decimal points, but with limited
precision like 3.14, -0.5)

//float example
float car_price = 299.9999999;

double (Similar to float, but stores numbers with more precision (more digits after the decimal). Good for scientific or financial calculations.)

//double example
double pi = 3.141592653589793

char (Stores a single character, like 'A', 'z', or '9')

char a = '9';

There are more of them but let's get the basic understanding first from them.

Understanding about writing characters
If you have been careful, you might have noticed that in the first example we wrote:

int car = 5;   // a number

But later we wrote:

char a = '9';  // a character

Notice the difference?

When we write a value without quotes (like 5), the computer understands it as a number that can be used in calculations.
When we write something inside quotes, the computer treats it as text/character data instead of a number.

Important detail:
Single quotes ' ' are used for a single character (like '9', 'A').
Double quotes " " are used for strings (text with one or more characters, like "Hello" or "9").
So:

5 → number (int), can be used in math.
'9' → character, not directly usable in math.
"9" → string (text), also not directly usable in math. These were some basic datatypes. There are more datatypes like string, Boolean etx but it can get confusing for you to remember too many datatypes as a beginner, and you can learn them later.

If you still didn’t understand datatypes, it might be because you missed the first part where I explained it with the example of an almirah and shelves. Imagine you have a box labeled “CAR” that contains your toy car. The box is like a variable holding the value “car.” Now, to keep your boxes safe, your mom gives you an almirah with three shelves — one for books, one for stationery, and one for toys. These shelves represent different datatypes. If you place your toy on the shelf meant for books, it will be confusing and hard to find, so you must place it on the toy shelf instead. Similarly, in programming, every value needs to be stored in the right datatype so that computer can understand.

Do not start to learn programming before this (Programming Fundamentals Part — 1)

Pixel and Code — Sun, 07 Sep 2025 04:13:53 +0000

Hello everybody,

Recently, I tried learning multiple programming languages at the same time (for those curious, I was working on C, C++, JavaScript, and Python). At first, I assumed they would all be completely different since they are used for different purposes. But I quickly realized something interesting: their basics are almost the same, with only a few differences and extra features here and there.

What I’m trying to say is this: the fundamentals of programming remain the same no matter which language you choose. And once you understand these fundamentals, learning any programming language becomes much easier and faster.

That’s exactly why C is often recommended as the first language to learn — it gives you a clear understanding of the fundamentals. In this series, I’ll explain these fundamentals to you as if you’re 5 years old.

But before we start, let me tell you this: You’ll be learning the fundamentals across multiple blogs, not in one giant post. This way, you won’t get bored reading a long wall of text.

This is Part 1 of the series.

So, let’s get started! 🚀

Variables

Ok, let’s assume you have a toy car. You want to keep your car in a safe place so that it doesn’t get lost. So, you find a box to store it. But there’s one problem — you have multiple boxes, and you might forget which one contains the toy car. What will you do? You’ll write CAR in big letters on that box. Now you’ll always know which box holds your car.

Congratulations! That’s it — you’ve already learned what a variable is.

Now, let’s see how this is defined in a programming language.

int car = 1;

int → This tells the computer that the box will store a whole number.
car → This is the name of the box (the variable). Just like labeling a box CAR, this name tells you what’s inside.
= 1; → This puts the value 1 into the box. It’s like putting one toy car inside the labeled box.
So, this single line creates a variable named car and stores a value in it.

You probably had a question in your mind now that why we write int in front of car? because computer reserves space differently for each data type. if you write int in front of the car. it will understand that user is trying to create a variable to store whole numbers, so it reserves 4 bytes in the ram for car variable but let's say that you want to store your name or may be a number something like 1.1, 2.009. What will do. Well, it will be explained later in the blog to keep you interest.

if you already understood why we write int, great you can skip to next para but if you didn’t it is completely ok and let me explain you in simple language. Now we know that you have a box named CAR with car toy inside it. Let's say you need a place to keep that box now. You do not want to keep it where it can get lost, right. Your mom already knew this that if any of toys got lost, you will cry. So, she made you a little almirah (cupboard) with different shelves. On the top shelfs you can keep your books, on the second shelf you can keep your stationary and on the third shelf you can keep your toys. Now if you keep your box at some other shelf than third shelf (toy shelf) you can get confused while finding your toy car later. That is why you keep the box in the third shelf name toys. That toy shelf is the type of your data. In programming we are saying to the computer that store car variable the integer shelf.

[Why variables are important? Answer is simple the data to access later. I am sure you have played a game which had score system. That score is stored in a variable. if there were no variables, maybe you would not have had scores system in games.]

If you have any questions, or if something wasn’t clear, feel free to ask in the comments — I’ll be happy to explain it better.

Part 2 is coming soon! The exact date depends on my motivation 😊. If I get good responses, I might publish it as soon as tomorrow. Otherwise, it could take a few days.