JSON-PARSE

JSON.parse()

its used to convert text into a JavaScript object

A common use of JSON is to exchange data to/from a web server.

When receiving data from a web server, the data is always a string.

We can check what type is currently here.

using typeof() we can find the type

Ex:

var str='{"name":"John", "age":30, "city":"New York"}';

alert(typeof(str));its shows string

after converting text into oject

var o=JSON.parse(str);

alert(typeof(str));now its shows object

For example

if we receive data like this

'{"name":"John", "age":30, "city":"New York"}'

Now we convert text into object

const obj = JSON.parse('{"name":"John", "age":30, "city":"New York"}');

Make sure the text is in JSON format, or else you will get a syntax error.

Parsing Dates
Date objects are not allowed in JSON.

If you need to include a date, write it as a string.

You can convert it back into a date object later.

const text = '{"name":"John", "birth":"1986-12-14", "city":"New York"}';
const obj = JSON.parse(text);
obj.birth = new Date(obj.birth);

Parsing Functions

Functions are not allowed in JSON.

If you need to include a function, write it as a string.

You can convert it back into a function later.

Convert a string into a function:

const text = '{"name":"John", "age":"function () {return 30;}", "city":"New York"}';
const obj = JSON.parse(text);
obj.age = eval("(" + obj.age + ")");

You should avoid using functions in JSON, the functions will lose their scope, and you would have to use eval() to convert them back into functions.