Day:8 - JS Scope

Scope in JavaScript

Scope determines where your variables can be seen, accessed, or used in your code. Think of scope as a security border around your variables.

Global Scope vs. Block / Local Scope

1. Global Scope: Variables declared outside of any function or code block {}. They can be accessed from anywhere in your entire JavaScript file.

2. Block / Local Scope: Variables declared inside a specific code block {} (like inside an if statement, loop, or function). They exist only inside those curly braces and cannot be seen from the outside.

Keyword Access Barriers (let / const vs. var)

Modern JavaScript uses let and const, which respect Block Scope {}. Legacy JavaScript used var, which ignores block boundaries and leaks outside curly braces!