JavaScript Objects
A JavaScript object is an entity with state and behavior, represented by
properties and methods. Examples include a car, pen, bike, chair, glass,
keyboard, monitor, etc.
JavaScript is an object-oriented language where everything is treated as an
object.
JavaScript is template-based, not class-based. Instead of creating classes
to generate objects, we directly create objects.
Creating Objects In JavaScript
There are three ways to create objects:
1. Using an object literal.
2. By directly creating an instance of Object using the `new` keyword.
3. By using an object constructor with the `new` keyword.
JavaScript Object By Object Literal
The syntax for creating an object using an object literal is shown below:
Syntax:
let objectName = {
propertyName1: value1,
propertyName2: value2,
propertyName3: value3,
};
As you can see, the property and value are separated by a colon (:).
Let’s look at a simple example of creating an object in JavaScript.
Example:
<Script>
let car = {
color: 'red',
model: 'Toyota',
year: 2004
};
console.log(car.color);
console.log(car.model);
console.log(car.year);
</Script>
Output :
Red
Toyota
2004
By Creating Instance Of Object
The syntax for creating an object directly is shown below:
Syntax:
let objectName = {
property1: value1,
property2: value2,
property3: value3,
...
};
In this case, the `new` keyword is used to create the object.
Let’s look at an example of creating an object directly.
Example:
<Script>
let person = {
name: 'Anya',
age: 19,
city: 'Chennai'
};
console.log(person.name);
console.log(person.age);
console.log(person.city);
</Script>
Output:
Anya
19
Chennai
By Using An Object Constructor
Here, you need to create a function with arguments. Each argument value can
be assigned to the current object using the `this` keyword.
The `this` keyword refers to the current object.
An example of creating an object using an object constructor is shown below.
Example:
<Script>
let person = new Object();
person.name = 'kakashi';
person.age = 23;
person.city = 'Chennai';
console.log(person.name);
console.log(person.age);
console.log(person.city);
</Script>
Output:
Kakashi
23
Chennai
Defining Method In JavaScript Object
In JavaScript, you can define a method in an object, but before defining the
method, you need to add a property with the same name as the method in the
function.
Example:
<Script>
let person = {
name: 'Anya',
age: 19,
city: 'Chennai',
greet: function() {
console.log('Hello, my name is ' + this.name);
}
};
person.greet();
</Script>
Output:
Hello, my name is Anya
JavaScript Object Methods
The different methods of Object are as follows:
More topic in JavaScript
