Let’s prepare for school

Everything works. Global variables do not affect the function in any way.

Our example works, but it is tightly associated with the value inside the collectContainer function. Maybe the student doesn’t want to just eat pasta every time? We need to offer him a choice. And more often than not, we pass some values to the function, and we do not rigidly record them inside the local scope. Add a parameter to the collectContainer function.

var collectContainer = function (food) {
  return function () {
    console.log('I ate ' + food);
  };
};

var schoolkid = collectContainer('pasta');
schoolkid();
// Outputs: I ate pasta.

Now the value of food will be taken from the parameter, and not from the local variable of the collectContainer function. Everything will work exactly the same. The function that collectContainer returns will remember the value of the parameter and use it when it makes a call.

We made the internal function anonymous because the name eatDinner is not used anywhere. It does not affect the operation of the function in any way.

Imagine now that we have two students. Each of them brings a lunchbox of food from home.

Make sure that when the global variables are redefined that it does not affect the operation of our collectContainer function.

Note that each time that we call the collectContainer function and write the result to a variable, a new closure is created in the memory that will remember the value of the food parameter at the time that it is created.