This document discusses representing JavaScript objects in JSON format. It provides examples of representing different data types like numbers, strings, arrays, and nested objects in JSON. It also gives examples of representing real world objects like a fish, book, university, and subjects in JSON. The document explains how to represent more complex nested objects like a university with multiple departments in JSON.

1. Web Technologies – CS 382
Shehzad Aslam
Lecture 6
1 Hr

2.  Creating Objects in JavaScript
 Introduction to Data formats & JSON
 Representing Objects in JSON
 Representing Arrays in JSON
 Nested Objects or Arrays in JSON

3.  Object is any real world thing having
properties and behaviors
 We are going to see only properties not
behaviors
var objectname = {
property: value,
property:value
};
var fish= {
name: “tuna”,
weight:150,
color: “black & gray”
};
To access properties
 Dot notation
Objectname.property;
fish.name
 Map (associative array,
dictionary, hash table)
notation
Objectname[“property”];
fish[“name”]

4.  Create a Cat object
 name, food, age, color
 Create a chocolate object
 Company, price, packing
 Create a book object
 Title, author, pages, publisher
 Create a university object
 Name, location, number of campus, area, num_departments, head name

5.  Index based
var arrayname= new Array();
//then use push method
OR
var counting= [1,2,3,4];
var name = [“Ali”, “Umer”];
Or
var a = [“This”, 23, “2@df”];
To access Elements
arrayname[index];
counting[2];
name[1];
a[2];

6. var subject= {
session: 2014,
subjects: [
“Web Technology”,
“OOAD”,
“Computer Networks”
],
level: 6
};
Or could be nested objects, nested arrays or
any combination of both
To access OOAD
subject.subjects[1]
OR
Subject[“subjects”][1]

7. Why data? We have to provide or consume it.
 Can be CSV
 Tabular format may be comma separated
 XML
 Tag based just like HTML tags
 JSON
 Represent JavaScript objects
 Can Represent primitives, Object or Array

8. var counting= [1,2,3,4];
Will be
[
1,
2,
3,
4
]
var name = [“Ali”, “Umer”];
Will be
[
“Ali”,
“Umer”
]

9. Java
Script
Object
Notation
var objectname = {
property: value,
property:value
};
Will be
{
“property”:value,
“property”:value,
}
var fish= {
name: “tuna”,
weight:150,
color: “black & gray”
};
?
{
“name”: “tuna”,
“weight”:150,
“color”: “black & gray”
}
Just like so mixed objects
This data could be in new file with
json extension

10.  Create a Cat object
 name, food, age, color
 Represent In JSON
 Create a chocolate object
 Company, price, packing
 Represent In JSON
 Create a book object
 Title, author, pages, publisher
 Represent In JSON
 Create a university object
 Name, location, number of campus, area, num_departments, head name
 Represent In JSON
 Create a list of subject objects
 Each subject has code, title, credit hours, and teacher
 Represent In JSON

11.  Represent University Department in JavaScript Object & in
JSON
 Name, Head Name, Started, Programs offered (array), total students, total
faculty
 Create a university object
 Name, location, number of campus, area, num_departments, head name
 University has 3 departments
 Department of Business Management
 Department of Pharmacy
 Department of Mathematics
 Each department has above information given in example
 Represent in JSON

12.  Represent RCET in one Object
 Departments (array)
 Each department having name, hod name, faculty list (each faculty name, qualification),
no of students in each session
 Cafeteria (array) with list of food items each item having category, served
weight and price
 Playgrounds (array) with description, area
 Hostels (array) with name, warden, rooms (array) with each room resident
name
 Represent your time table in one object

13.  JSON validator
 Use http://jsonlint.com/ to validate your json
 Practical usage will be in next Lecture