Day -18 My JavaScript Journey Begins: Understanding the Basics

JavaScript Basics: Data Types, Variables, Functions, and More

Today, I continued my JavaScript journey by diving into some of the core concepts that every developer needs to know. Here's a breakdown of what I learned and some examples that helped me understand things better

1. Data Types in JavaScript

JavaScript supports several basic data types:

• String – Text enclosed in quotes

  let name = "Tamil";

• Number – Integers or floating-point numbers

  let age = 25;

• Boolean – true or false

  let isStudent = true;

• Undefined – A variable declared but not assigned

  let score;

• Null – Intentionally empty

  let result = null;

2. Variables

Variables are used to store data values. You can declare them using var, let, or const.

let city = "Coimbatore";
const country = "India";

I learned that const is used when we don't want to reassign a value, while let allows reassignment

3. Functions

Functions are blocks of reusable code. They help us avoid repeating code.

Function Declaration

function greet() {
  console.log("Hello, World!");
}

Calling a Function

greet(); // Output: Hello, World!

4. Parameters and Return Values

Functions can take inputs (parameters) and return outputs using the return keyword.

function add(a, b) {
  return a + b;
}

let sum = add(5, 10);
console.log(sum); // Output: 15

5. String Concatenation

Joining strings together is called concatenation.

let firstName = "Tamil";
let lastName = "Selvam";
let fullName = firstName + " " + lastName;
console.log(fullName); // Output: Tamil Selvam

I found it exciting to see how functions and variables work together to create dynamic outputs!

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Final Thoughts

Learning these foundational concepts is like building blocks for my JavaScript journey. I feel more confident now in writing basic code and understanding how logic flows in a program . Tomorrow, I’ll be moving on to conditional statements and loops!

Thanks for reading! If you're also learning JavaScript, feel free to connect—we can grow together

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