Lexical Scope

Read an outer variable from inside a function.

lexical_scope.js

const base = ;

function addBase(x) {
  return base + x;
}

const r1 = addBase(5);
const r2 = addBase(8);

console.log("r1=" + r1);
console.log("r2=" + r2);

const base = ;

function addBase(x) {
  return base + x;
}

const r1 = addBase(5);
const r2 = addBase(8);

console.log("r1=" + r1);
console.log("r2=" + r2);

const base = ;

function addBase(x) {
  return base + x;
}

const r1 = addBase(5);
const r2 = addBase(8);

console.log("r1=" + r1);
console.log("r2=" + r2);

lexical-scope A function can read variables from the scope where it is defined. Here `addBase` uses the outer `base` every time it runs.