functionsasabstractions.js

/*
	Instead of repeating cross-cutting concerns in every function, we
	can use the "doWork" function as an abstraction.
*/

var work = function(){
	console.log("working hard");
};

var doWork = function(func){
	console.log("starting");
	try { 
		func();
	}
	catch(ex){
		console.log(ex);
	}
	console.log("ending");
};

doWork(work);

iffe.js

// Immediately invoked function expression or IFFE.
(function() {
  var createFunc = function() { 
    return function () { 
      console.log("hello.");
    }
  }
  var func = createFunc();
  func();
})();

revealingmodulepattern.js

// Revealing module pattern.
var createWorker = function(){
  // Encapsulate code inside of a function/module.
  var job1 = function() {
    console.log("job1");
  };
  var job2 = function() {
    console.log("job2");
  };
  return {
    job1: job1,
    job2: job2
  }
};

var worker = createWorker();
worker.job1();
worker.job2();