Objects in JavaScript | Nested Objects in JavaScript | JavaScript Course for Beginners
In this video, I have discussed about ojects in javascript
#object #javascript #parnikatutorials
JavaScript object is a non-primitive data-type that allows you to store multiple collections of data.
Note: If you are familiar with other programming languages, JavaScript objects are a bit different. You do not need to create classes in order to create objects.
Here is an example of a JavaScript object.
// object
var student = {
Name: 'jagadeesh',
age: 35
};
Here, student is an object that stores values such as strings and numbers.
avaScript Object Declaration
The syntax to declare an object is:
var object_name = {
key1: value1,
key2: value2
}
Here, an object object_name is defined. Each member of an object is a key: value pair separated by commas and enclosed in curly braces {}.
For example,
// object creation
var person = {
name: 'Jagadeesh',
age: 20
};
console.log(typeof person); // object
Accessing Object Properties
You can access the value of a property by using its key.
1. Using dot Notation
Here's the syntax of the dot notation.
objectName.key
For example,
var person = {
name: 'John',
age: 20,
};
// accessing property
console.log(person.name); // John
Using bracket Notation
Here is the syntax of the bracket notation.
objectName["propertyName"]
For example,
var person = {
name: 'John',
age: 20,
};
// accessing property
console.log(person["name"]); // John
JavaScript Nested Objects
An object can also contain another object. For example,
// nested object
var student = {
name: 'John',
age: 20,
marks: {
science: 70,
math: 75
}
}
// accessing property of student object
console.log(student.marks); // {science: 70, math: 75}
// accessing property of marks object
console.log(student.marks.science); // 70
JavaScript Object Methods
In JavaScript, an object can also contain a function. For example,
var person = {
name: 'Sam',
age: 30,
// using function as a value
greet: function() { console.log('hello') }
}
person.greet(); // hello
Run Code
Here, a function is used as a value for the greet key. That's why we need to use person.greet() instead of person.greet to call the function inside the object.
