What is the difference between function scope and block scope in JavaScript?

What is the difference between function scope and block scope in JavaScript?

Function scope means that variables are accessible within the function they are declared in, while block scope restricts access to the block (like loops or conditionals) they are defined in.

Can you give me an example of each?

Sure! For function scope, if you declare a variable inside a function, it can't be accessed outside of it. For block scope, if you declare a variable with 'let' or 'const' inside a block, it won't be accessible outside that block.

What happens if I use 'var' inside a block?

Using 'var' inside a block will still make the variable accessible outside the block, as 'var' has function scope, not block scope.

Why should I prefer 'let' and 'const' over 'var'?

'let' and 'const' provide block scope, which helps prevent variable hoisting issues and makes your code more predictable.