How to create a JavaScript object?
The JavaScript
object is a collection of properties and the each
property associated with the name-value
pairs. The object can contain any
data types (numbers, arrays, object etc.)
The example
looks like,
Var myObject= {empId :
“001”, empCode :”X0091”};
In
the above example, here are two properties one is empId and other is empCode
and its values are “001” and “X0091”.
The
properties name can be string or number. If a property name is number i.e.
Var numObject= {1 :
“001”, 2 :”X0091”};
Console.log(numObject.1);
//This line throw an error!
Console.log(numObject[“1”]);
// will access to this line not get any
error!
As
per my thought, the number property name should be avoided.
Types
of creating an object (There are two types)
1.
Object literals
2.
Object constructor
Object Literals:
This is the most common way to create an object with object literal and the example
as given below.
The
empty object initialized using object literal i.e.
var emptyObj= {};
This
is an object with 4 items using object literal i.e.
var emptyObj ={
empId:”Red”,
empCode: “X0091”,
empDetail : function(){
alert(“Hi”);
};
};
Object
Constructor: The second way to create object using
object constructor and the constructor is a function used to initialize new
object.
The
example looks like,
Var obj = new Object();
Obj.empId=”001”;
Obj.empCode=”X0091”;
Obj.empAddressDetai = function(){
Console.log(“Hi, I Anil”);
};
Summary:
There is no best way to create an object. It’s
depending on your uses case. You can choose all one as per your case. All have
some benefits.
There are some styles are available to create an
objects,
1.
Object Constructor,
2.
Literal Constructor,
3.
Function Based,
4.
Prototype Based,
5.
Function and
6.
Prototype Based Singleton Based.
JavaScript
Object Prototypes Based -
All JavaScript objects inherit properties and
methods from a prototype.
We can only modify own prototypes and we will never
modify the prototypes of standard JavaScript objects.
All below objects inherit from Object.prototype -
1. Date
objects
2. Array
objects
3. Person
objects
The date objects inherit from Date.prototype and the array objects
inherit from Array.prototype and
also the Person objects inherit from Person.prototype.
Sometimes we have a requirement to add new properties and methods in the existing objects or constructors.
Example for add new properties to object
constructors –
//Person
function Person(firstName, lastName, age) {
this.firstName = firstName,
this.lastName = lastName;
this.age = age;
}
//Person prototype
Person.prototype.nationality = "Indian";
Example for add new methods objects constructors –
//Person Peroperty class
function Person(firstName, lastName, age) {
this.firstName = firstName,
this.lastName = lastName;
this.age = age;
}
//Person prototype
Person.prototype.fullName = function() {
return this.firstName + " " + this.lastName;
};
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Anil Singh is an author, tech blogger, and software programmer. Book writing, tech blogging is something do extra and Anil love doing it. For more detail, kindly refer to this link..
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