JavaScript_Succinctly

pretty handy when you need more than two or three objects that possess the same
properties, but with different values. Come to think of it, this is exactly what JavaScript
does with the native objects. The Person() constructor follows the same principles as
the Array() constructor. So new Array('foo','bar') is really not that different than
new Person(true, 33, 'male'). Creating your own constructor functions is just
using the same pattern that JavaScript itself uses for its own native constructor
functions.
Notes
It is not required, but when creating custom constructor functions intended to be used
with the new operator, it’s best practice to make the first character of the constructor
name uppercase: Person() rather than person().
One tricky thing about constructor functions is the use of the this value inside of the
function. Remember, a constructor function is just a cookie cutter. When used with the
new keyword, it will create an object with properties and values defined inside of the
constructor function. When new is used, the value this literally means the new object or
instance that will be created based on the statements inside the constructor function.
On the other hand, if you create a constructor function and call it without the use of the
new keyword, the this value will refer to the "parent" object that contains the function.
More detail about this topic can be found in Chapter 6.
It's possible to forgo the use of the new keyword and the concept of a constructor
function by explicitly having the function return an object. The function would have to be
written explicitly to build an Object() object and return it: var myFunction =
function() {return {prop: val}};.
Instantiating constructors using the new operator
A constructor function is basically a cookie-cutter template used to create preconfigured
objects. Take String() for example. This function, when used with the new
operator (new String('foo')), creates a string instance based on the String()
"template.” Let's look at an example.
Sample: sample9.html
var myString = new String('foo');
console.log(myString); // Logs foo {0 = "f", 1 = "o", 2 = "o"}
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