JSFiddle - React, Tailwind, and code Playground

JavaScript

function f(x){
  var a = 10;
  return a*x;
}
console.log(f(6));//60

function f(x){
  var a = 10;
  return a*g(x);
  function g(b){
    return b*b;
  }
}
console.log(f(6));//360

function f(x){
  var a = 10;
  return a*g(x);
  function g(b){
    var a = 1;
    return b*b*a;
  }
}
console.log(f(6));//360, not 3600

var a = "outside";
function f(){
  var a = "inside";
  function g(){return a;}
  return g;
}
var result = f();

console.log(result());//inside