scope and scope chain example with comments

scope-scope-chain-commented.js

// scope & scope chain commented

// was declared globally, outer reference is global
function a() {
  // variable created inside context of a
  var myOtherVar = 'inside A'

  // b called inside a, but was lexically declared in the global context
  b()
}

// was declared  globally, outer reference is global
function b() {
  // variable exists in b
  var myVar = 'inside B'

  // goes up to the global context, fetches myOtherVar and logs it
  console.log('myOtherVar:', myOtherVar)

  // was declared inside b, outter reference is b
  function c() {
    // goes into the context of function b and logs myVar
    // it stops after finding the variable
    // meaning it does not go up again to the global scope unless it needs to
    console.log('myVar:', myVar)
  }

  c()
}

// global variables
var myOtherVar = 'global otherVar'
var myVar = 'global myVar'

a()