Local (Function-level) Scope

local.scope.js

let name = 'Fortune';

function func() {
  let age = 22;
  console.log(name, age);
}

func() // 'Fortune 22'

// Accessing age here throws
console.log(age) // Uncaught ReferenceError: age is not defined

/**
 * Variable declared without the var, let or const keyword 
 * gets thrown into the function's outer scope
 */
function withoutVarLetOrConst() {
  out = 'Acessible within the outer scope';
}
withoutVarLetOrConst();
console.log(out); // -> 'Accessible within the outer scope'

// Variable "name" can be changed within a function scope
function changeName() {
  name = 'Rose';
}
// Calling the function modifies the global variable "name"
changeName();

console.log(name) // -> 'Rose'