Understanding Closures in Javascript

This example shows how you create a closure which uses an alert function that can be incremented and reused/passed around.

• In the console call funcStorer() and you will see the counter increment.
• Then call funcStorer2() and you will see a seperate counter increment.
• The variable x is private to the closureAlert function.
• When funcStorer is called closureAlert runs, it returns alerter.
• When functStorer is called again it doesn't call closureAlert again it calls what it returns alerter.

var closureAlert = function() {
  var x = 0;
  var alerter = function() {
    alert(++x);
  }
  return alerter;
}

var funcStorer = closureAlert(); // reference to alerter();
var funcStorer2 = closureAlert(); // second seperate reference to alerter();