𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗦𝗰𝗼𝗽𝗲: 𝗕𝗹𝗼𝗰𝗸, 𝗚𝗹𝗼𝗯𝗮𝗹, 𝗮𝗻𝗱 𝗙𝘂𝗻𝗰𝘁𝗶𝗼𝗻

𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗦𝗰𝗼𝗽𝗲: 𝗕𝗹𝗼𝗰𝗸, 𝗚𝗹𝗼𝗯𝗮𝗹, 𝗮𝗻𝗱 𝗙𝘂𝗻𝗰𝘁𝗶𝗼𝗻

Scope decides where you use a variable in your code.

1. Global Scope Variables live outside functions or blocks. You access them from anywhere in your script. Warning: Global variables lead to bugs because any part of your code can change them.

2. Function Scope Variables live inside a function. You only access them within that specific function.

3. Block Scope This applies to modern JavaScript using let or const. Variables live inside curly braces {}. A block includes:

• if statements
• for loops
• while loops
• standalone blocks {}

Summary of Scope:

• Global: Accessible everywhere.
• Function: Accessible only inside the function.
• Block: Accessible only inside the curly braces.
• var: Uses function scope. It ignores block scope.
• let and const: Use block scope. Use these for better code.

Understanding Processes and Threads

A process is a running program with its own memory. Think of WhatsApp as a process.

A thread is a small part of a process. Threads share the same memory.

• Threads are lightweight.
• They are fast to create.
• They allow you to do many things at once.

Example of WhatsApp: One process (WhatsApp) runs multiple threads:

• Receiving messages
• Sending photos
• Playing videos
• Showing notifications

Source: https://freeacademy.ai/lessons/global-vs-function-vs-block-scope Source: https://josephcardillo.medium.com/the-difference-between-function-and-block-scope-in-javascript-4296b2322abe