closures.js

var wrapper = function() {
  var internalVar = 1
  var internalFunction = function () {
    console.log("internalVar:", internalVar);
  }
  
  return internalFunction;
}

var capturedFunction = wrapper();

capturedFunction();

example.js

// obj1 is an object with a name and a function
// called printName
var obj1 = {
  name: 'obj1',
  printName: function () {
    console.log(this.name);
  }
}

// obj2 just has a name
var obj2 = {name: 'obj2'}

// call printName
obj1.printName();

// use "call" this time, passing in obj2 as the
// context argument.
obj1.printName.call(obj2);