JSON (JavaScript Object Notation)
What Is JSON?
- JSON is a text format for storing and transporting data.
- JSON is “self-describing” and easy to understand.
- JSON is a lightweight data-interchange format.
- JSON is used to send data between computers.
- JSON is language independent.
JSON Example
This example is a JSON string:
'{ "name":"John", "age":30, "car":null }'
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It defines an object with 3 properties: name, age, and car.
Each property has a value.
If you parse the JSON string with a JavaScript program, you can access the data as an object:
let personName = obj.name;
let personAge = obj.age;
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Why Use JSON?
The JSON format is syntactically similar to the code for creating JavaScript objects.
Because of this, a JavaScript program can easily convert JSON data into JavaScript objects.
Since the format is text only, JSON data can easily be sent between computers, and used by any programming language.
JavaScript has a built-in function for converting JSON strings into JavaScript objects:
JSON.parse( )
It also has a built-in function for converting an object into a JSON string:
JSON.stringify( )
You can receive pure text from a server and use it as a JavaScript object.
You can send a JavaScript object to a server in pure text format.
You can work with data as JavaScript objects, with no complicated parsing and translations.
Demonstration
The following demonstration shows how the script of HTML and JavaScript is displayed on the Web.
I love my phone machine. I wish I was a phone machine.
I wish if I saw somebody on the street I didn’t want to talk to
I could go “Excuse me, I’m not in right now.
If you could just leave a message, I could walk away.”
― Jerry Seinfeld
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