JSON and XML are used to share information over the internet. Both of these data types store information in a particular order where data is associated with a label or a tag.
In this guide, we discuss what JSON and XML are and what they are used for. We’ll walk through the pros and cons of each of these data types so you can learn why they are used.
What is JSON?
JSON, or JavaScript Object Notation, is a method of storing and sharing data.
A big use case of JSON is sending data from a client to a server. The client is the side of an application that shows a user information and the server is where that information is processed. Often, a client makes a JSON request and then a server returns the data requested in the JSON format to be processed on the client-side.
In JSON, data is separated using key-value pairs:
{ “name”: “Jason” }
There is one key and one value in this JSON object. “name” is the key and “Jason” is the value associated with that key.
What is XML?
XML, or eXtensible Markup Language, is another method of sharing data.
Like JSON, XML is widely used in web development. It is used to structure data that will be processed by other programs or web services.
A common use case of XML is an RSS feed. In an RSS feed, information such as article and podcast metadata is stored in a feed. This information can be interpreted by a feed reader who turns the raw data into a functional application.
Information in the JSON data format is stored with tags:
<?xml version="1.0" encoding="UTF-8"?> <root> <company> <name>Career Karma</name> </company> </root>
Our data has two tags: root, company and name. The “name” tag is part of the “company” tag which tells us the “name” data point is related to the company tag in which it is enclosed.
The Advantages of JSON
JSON is incredibly easy to use. Because it is standard, there is vast support for storing and processing data in JSON. JavaScript, for instance, comes with built-in JSON support. The Python programming language has a built-in library to process JSON data.
JSON data is easy to read. While this is not necessarily crucial because it is mainly processed by humans, the fact that the data is easy to read makes it easier for developers to work with. Data is easily readable because there is a clear and standard structure in a JSON file.
The Advantages of XML
You can define any XML tag you want. Unlike HTML, another markup language, you do not have to depend on a set of tags when you are using XML. This is because XML is used to describe data. Data can take many forms and no one set of labels describes every data set.
XML markup, like JSON markup, is easy to read. This means if you are a developer working with XML, then it should not be too difficult to understand what data is being transmitted over an XML file.
JSON vs. XML
While JSON and XML both transmit data, they do so in very different ways.
In JSON, data is mapped as keys and values. XML, on the other hand, depends on tags. You can choose whatever names you want for your keys in JSON and tags in XML. This is because every program has different data transmission needs.
JSON is stored in a JSON object, which is widely supported by most programming languages. XML, on the other hand, requires a parser to interpret.
This makes XML slightly more inaccessible because you have to learn how to use a parser to read the contents of a document into a program. With that said, once a parser has been set up, you will be ready to work with XML throughout an application.
XML is more widely used to describe data. This is because it is a markup language. HTML, the markup language that determines the structure of a web page, describes to a browser exactly how a web page should be rendered. XML describes exactly what data is being transferred and how that data relates to each other.
In both JSON and XML, data is human-readable and easy-to-understand. What’s more is that both technologies are language-independent: you can use them with most major languages, even if you do need a parser to work with XML.
When to Use JSON and XML
JSON is a good choice if you want to transmit data from a client to a server. JSON data is readily processed by most programming languages. This means that you will not have to do any data parsing on either the client or the server side after data has been sent.
XML is good if you need to separate data from HTML.
Whereas HTML is designed to describe how a web page should be structured, it does not always include the data that computers may need. In an XML file, you can mark up all the data a computer may need to work with an application.
The Bottom Line
Both XML and JSON have their own use cases. XML is often used to share articles and podcasts over RSS or to describe data in a web application. JSON, on the other hand, is more commonly used to transmit data between clients and servers.
As a programmer, you’ll probably end up working with both of these data types at some point. JSON is generally learned before XML because it is easier to understand and has built-in support in many programming languages. If you need to describe a data set and JSON does not fulfill your requirements, XML may be an option.
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