JSON Vs XML - Key Differences

What is JSON (JavaScript Object Notation)?

JavaScript Object Notation (JSON) serves as a data-interchange format designed to store and transmit data objects in a manner that is easily readable by humans. Unlike many formats that are tied to a specific programming language, JSON stands out for its lightweight and language-independent nature. Although its syntax finds its roots in the JavaScript programming language, it’s crucial to understand that JSON is entirely independent of any language. This independence means that while JSON data can be read and generated using JavaScript, the same can be accomplished using numerous other programming languages. All data stored in this format is saved with the .json extension and can include a range of data types, including strings, numbers, booleans, and nulls. The structure of JSON data often involves JSON Objects and JSON Arrays, which are essential components in the storage and transfer of data across the web. These elements will be delved into in greater detail later in this article.

1. JSON Objects:

JSON objects are used to store and transfer data across the web. Objects in JSON store data in key-value pairs. Key-value pairs are related elements where a Key is a constant that defines the data set while a value is a variable of that data set. For eg. "color" can be a key and colors like "blue", "red", etc. can be the values.

Keys in JSON objects should be strings, and values can be of any valid JSON data type. JSON objects are enclosed in curly braces, i.e., {}, while the keys & values are separated by a colon, i.e., :, and each key-value pair is separated by a comma.

Example:

Above is the key-value pair that stores data related to a book. Here, book_name, author, and genre are the keys, and their related values are there in the values part.

2. JSON Arrays:

Arrays in JSON are just like arrays in any other programming language. JSON arrays are a list of objects enclosed in square brackets, i.e., []. Values stored in JSON array can be of data types string, number, object, boolean or null. JSON arrays can be a list of JSON objects which means multiple key-value pairs can be stored in a single array.

Example:

The above array shows the availability of cars in a car showroom. Each element of the array is a JSON object that stores data in the form of key-value pairs. Here, the objects have information about distinct cars like their id, names, and if they are present in the showroom or not.

History of JSON

• JSON format was specified by Douglas Crockford in the early 2000s.
• Official website of JSON was launched in 2003.
• JSON was created to hold the structured data that could be used in javascript. But it became so popular that it is used to transfer data for all kinds of applications.
• Yahoo! was the first company to start offering its web services in JSON in 2005.
• JSON became ECMA international standard in 2013.
• In 2017, the most updated format standard of JSON was published.

What is XML (Extensible markup language)?

XML, or eXtensible Markup Language, is a system designed primarily for data storage and has become a popular medium for distributing data across the internet and various application programming interfaces (APIs). At its core, XML is a markup language, characterized by a set of symbols rendered in a way that both humans and computers can interpret seamlessly. Unlike some languages which are meant for both storing and displaying data, XML’s main function is to store and transfer data; it doesn’t possess the inherent tools to present data aesthetically. One of the reasons for XML’s widespread adoption is its compatibility with numerous programming languages. Virtually every programming language today is equipped with a parser for XML, making it easy to fetch and validate data stored in this format.

A distinguishing feature of XML is its provision to store namespaces. In essence, a namespace acts as a unique container or group wherein specific elements and attribute names are housed. This mechanism facilitates differentiation, especially when elements originate from different sources. Another important aspect of XML is its ability to store metadata—essentially, data about data. This could range from information regarding the source of files to more nuanced details. Interestingly, XML tags themselves can be viewed as a form of metadata since they provide context to the type of data or attribute they encapsulate.

With the rapid digitization of various sectors such as e-banking and online shopping, XML’s role has become increasingly pivotal. Its structure mandates case sensitivity and primarily uses tags for data storage. These tags in XML bear a resemblance to those found in HTML. They are demarcated with <> to signify the beginning and </> for closure, and it’s imperative that the names of the starting and ending tags are identical. Furthermore, in XML, data can be handled in two primary ways, either through tags or attributes. Example:

The above example gives us an idea about XML file format and how tags are used in XML. Here <rainbow> is the main tag that has other sub-tags like <violet>, <red>, which display numeric values.

History of XML

• XML is derived from SGML(Standard Generalized Markup Language), which is an international standard for the definition of markup languages.
• SGML/GML was invented by Charles Goldfarb, Ed Mosher, and Ray Lorie in 1970.
• The development of XML started in the year 1996 at Sun Microsystem.
• First version of XML, XML 1.0 was released in February 1998.

Key Difference Between JSON and XML

The main difference between JSON and XML is their structure and purpose. JSON, or JavaScript Object Notation, is a lightweight data-interchange format that uses human-readable text to represent data structures. Originating from JavaScript, JSON has become language-independent and is primarily used for asynchronous browser/server communication. On the other hand, XML, or eXtensible Markup Language, is a markup language designed for storing and transporting data, without any focus on how the data looks. While both can be parsed by most programming languages, XML uses tags, is more verbose, and is extensible, whereas JSON utilizes a more compact key-value pair structure.

JSON Vs XML: Detailed Comparison

Structure of JSON vs XML

1. Structure of JSON

• JSON handles data in two ways JSON arrays and JSON objects.
• Data structural hierarchy of JSON is in map format. As it handles data in key-value pairs.
• It supports data types like string, number, boolean, array, and null.
• JSON arrays are a list of objects, enclosed in square brackets, i.e., [].
• Object in JSON are dictionaries that store data in key-value pairs. Keys in JSON objects should be string, and values can be of any valid JSON data type.
• JSON objects are enclosed in curly braces, i.e., {}, while the keys & values are separated by a colon, i.e., :, and each key-value pair is separated by a comma.
• Structure:

Here, the student is the array that stores the student's information in the form of key-value pairs.

2. Structure of XML

• XML handles data in two ways tags and attributes.
• These tags are case-sensitive.
• Tags in XML are similar to that of HTML. Tags start with <> and end with </>. Names of the start and end tags must match.
• The names of tags must only be letters, numbers, and underscore, and the tag name must start with a letter only.
• Structure:

Above is the structure of XML tags. And it shows the hierarchy of XML tags. XML follows a tree data structure. The tree starts at the root and branches to the lower level of trees. <root> tag is at the root of the tree.

Similarities Between JSON and XML

1. Both JSON and XML serve the same purpose of storing and transferring data across the web.
2. These are human-readable, easy to understand, and self-describing.
3. Both have parsers in most programming languages and APIs. The code in JSON and XML is converted into the code that is understandable by the compiler of the programming language in which it is used.
4. The data in both JSON and XML can be fetched from web servers using HTTP requests. HttpRequests is used to request data from servers. The methods used for fetching the data are GET, PUT, and POST.
5. JSON and XML support hierarchical structure, i.e., they store values within values.
6. Both JSON and XML are open source software, and the software code is publicly accessible anyone can see, modify, and distribute the code.

Advantages of Using JSON

• Easy to read and write due to simple syntax.
• Supported by all browsers and is recognized by JavaScript.
• Can be used with almost all programming languages and provides support for all browsers.
• Transmission of JSON files over browsers is much faster.
• Due to the increasing popularity of javascript, the use of JSON has been increasing.
• JSON supports different data types and key-value pairs, which makes it easy to understand.

Disadvantages of Using JSON

• JSON does not support namespace and cannot be extended.
• It lacks formatting validation, meaning incorrect data structures can be passed into your APIs.
• JSON is less secure compared to XML.

Advantages of Using XML

• XML separates data from normal HTML documents.
• It simplifies the platform exchange process.
• Support for different APIs and almost every programming language has XML parser.
• User-defined tags can be created in XML.
• XML does something that JSON cannot do – it can dress it up and allow languages like Java and C++ to create interfaces for applications that may not be web-based.

Disadvantages of Using XML

• The syntax used in XML is complex, and using tags makes it similar to other web-based programming languages, which makes it confusing.
• There is no data-type support in XML.
• XML files are bulky and require more size.

Read More:

• XML Formatter