Self-Learning Journey

Tracking my progress in IT

Links

🔐 Cybersecurity Notes

☁⚙ Cloud Computing & DevOps Notes

Programming Notes

🗄️ SQL Notes

1. SELECT - View Data

Used to display every record from a table.

Syntax: ```sql SELECT * FROM table_name; ``` Example: ```sql SELECT * FROM students; ```

2. INSERT - Add Data

Adds a new row into a table.

Syntax: ```sql INSERT INTO table_name(column1,column2) VALUES(value1,value2); ``` Example: ```sql INSERT INTO students(id,name,age,grade) VALUES(1,'Alex',20,'A'); ```

3. UPDATE - Modify Data

Updates existing records.

```sql UPDATE students SET grade='B' WHERE name='Alex'; ```

4. DELETE - Remove Data

```sql DELETE FROM students WHERE name='Alex'; ```

5. WHERE - Filter Records

```sql SELECT * FROM students WHERE age > 18; ```

6. ORDER BY - Sorting

```sql SELECT * FROM students ORDER BY age ASC; ```

7. COUNT()

```sql SELECT COUNT(*) AS total_students FROM students; ```

8. AVG()

```sql SELECT AVG(age) AS average_age FROM students; ```

9. GROUP BY

```sql SELECT grade, COUNT(*) AS total_students FROM students GROUP BY grade; ```

🐍 Python Notes

Variables

Variables store data.

```python name = "John" age = 20 ```

Input

```python name = input("Enter your name: ") print(name) ```

Type Conversion

```python marks = int(input("Enter marks: ")) ```

If Else

```python age = 18 if age >= 18: print("Adult") else: print("Minor") ```

While Loop

```python while guess != number: print("Try Again") ```

Random Numbers

```python import random number = random.randint(1,10) ```

f-Strings

```python print(f"Total: {total}") print(f"Percentage: {percent}%") ```

Data Types

int
float
str
list
tuple
set
dict

Java Basics Notes

Java is a high-level, object-oriented programming language designed to be platform-independent.
Key Features of Java
- Object-Oriented
- Platform Independent (Write Once, Run Anywhere)
- Secure and Robust
- Automatic Memory Management (Garbage Collection)

Basic Java Program Structure

class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

Java Data Types
- Primitive: int, float, double, char, boolean
- Non-Primitive: String, Array, Class, Interface

Variables

int age = 20;
double price = 99.99;
char grade = 'A';
boolean isActive = true;

Conditional Statements

int marks = 75;

if (marks >= 50) {
    System.out.println("Pass");
} else {
    System.out.println("Fail");
}

Loops

For Loop
While Loop
Do-While Loop

for (int i = 1; i <= 5; i++) {
    System.out.println(i);
}

Methods (Functions)

static void greet() {
    System.out.println("Hello from Java");
}

Object-Oriented Concepts (Basics)
- Class
- Object
- Encapsulation
- Inheritance
- Polymorphism
- Abstraction

Next Topics: Classes & Objects (deep), Constructors, Inheritance, Interfaces, Exception Handling.

HTML Notes

HTML stands for HyperText Markup Language.
Used to structure content on the web.

Basic elements:

<h1>Heading</h1>
<p>Paragraph</p>
<a href="url">Link</a>
<ul><li>List Item</li></ul>

HTML elements have tags and attributes.

CSS Notes

CSS stands for Cascading Style Sheets.
Used to style HTML content: colors, fonts, layout.

Basic example:

<style>
  body {
    background-color: lightblue;
  }
  h1 {
    color: navy;
  }
</style>

Selectors target HTML elements to apply styles.

JavaScript & TypeScript Notes (Smart Comparison)

JavaScript (JS) and TypeScript (TS) are closely related. TypeScript is a superset of JavaScript, meaning:
All JavaScript code is valid TypeScript code.

Main Difference
- JavaScript → Dynamic typing
- TypeScript → Static typing + JavaScript features

Basic Variable Declaration

JavaScript:
let age = 25;

TypeScript:
let age: number = 25;

Data Types

JavaScript:
let name = "Alex";
let isActive = true;

TypeScript:
let name: string = "Alex";
let isActive: boolean = true;

Functions

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

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

Arrays

JavaScript:
let numbers = [1, 2, 3];

TypeScript:
let numbers: number[] = [1, 2, 3];

Objects

JavaScript:
let user = {
    name: "Sam",
    age: 22
};

TypeScript:
let user: {
    name: string;
    age: number;
} = {
    name: "Sam",
    age: 22
};

Why TypeScript Exists
- Catches errors at compile time
- Better code readability
- Great for large applications
- Excellent IDE support

Compilation Flow

TypeScript (.ts)
      ↓
Compiled to JavaScript (.js)
      ↓
Runs in Browser / Node.js

Where They Are Used
- JavaScript → Browsers, Node.js, web apps
- TypeScript → Angular, React, enterprise apps

Learning Strategy: Learn JavaScript fundamentals first, then move to TypeScript for safer and scalable code.

Next Steps

Gradually add more notes, code examples, and learning resources for each field.

Links

🔐 Cybersecurity Notes

☁⚙ Cloud Computing & DevOps Notes