Convert JSON to String

Let’s discuss regarding convert Javascript JSON ( Javascript Object Notation ) to string or javascript JSON to string.

We are using JSON.stringify() for JSON to string converter.

Let’s check with an example:

let json_string = JSON.stringify({ Class: 1, Subject: 6 })

console.log(json_string);

//Output: "{"Class":1,"Subject":6}"

In the above example :
let used for declaring the variable in javascript.
JSON.stringify() method converts a JavaScript value into a JSON string.
console.log() method print value in the console of the browser.

let’s convert a JavaScript array to JSON:

var prog_lang = ['javascript', 'ruby', 'java', 'c'];

var json = JSON.stringify(prog_lang); 

// '["javascript","ruby","java","c"]'

JSON.stringify with Unsupported Data Types

Supported JSON Data types:

- Strings
- numbers
- booleans
- null
- arrays
- objects

Un – supported JSON Data types:

- Date objects
- regular expressions
- undefined
- functions

Let’s Check with Example:

var json_unsupported = {
    name: 'Test',
    no: 10,
    date: new Date(),
    code: ['c', 'c++', 'java'],
    object: {
        no: 10,
        like: true,
        name: null,
        value: undefined,
        exp: /^\d+$/,
        fun: function(value) {
            // code here
        }
    }
}

var json_string = JSON.stringify(json_unsupported);
console.log(json_string);

/*
{"name":"Test","no":10,"date":"2018-10-28T03:07:00.520z",
"code":["c,"c++","java"],
"object":{"no":10,"like":true,"name":null,"exp":{}}}
*/

In the above example:

var used for declaring the variable in javascript.
JSON.stringify() method converts a JavaScript value into a JSON string.
console.log() method print value in the console of the browser.
exp (regular expression) – has been converted to an empty object.
name with undefined – has been removed.
fun (function) with values has been removed.

JSON.stringify with Indent or Space:

JSON.stringify’s output does not contain default white space. it compact for data transmission but difficult to read. So we can use its optional argument for space or indent.

var json_data = {
    name: 'Test',
    no: 10,
    date: new Date(),
    code: ['c', 'c++', 'java'],
    object: {
        no: 10,
        like: true,
        name: null
    }
}

var json = JSON.stringify(json_data, null, 4);
console.log(json);

/* output of console.log with indent of 4
{
    name: 'Test',
    no: 10,
    date: new Date(),
    code: ['c', 'c++', 'java'],
    object: {
        no: 10,
        like: true,
        name: null
    }
}

In the above example, the third argument is 4 and its use for indent. The second argument was passed as null because we need the third argument for indent.

You can refer to https://www.learningcontainer.com/json-example/ for the JSON format example.

You can compare JSON file, data and URL on https://jsoncompare.org its best tool for comparing with details.
You can format your JSON file and URL and Data directly on https://jsonbeautifier.org – it is a very powerful and easy tool for view JSON data.