how to use the parsejson function from the date-fns library in typescript

To use the parseJSON function from the date-fns library in Typescript, we need to install the @types/date-fns package as a development dependency. This package contains the type definitions for the date-fns library that we need to use in Typescript.

Assuming that we have date-fns and @types/date-fns installed, we can use the parseJSON function as follows:

index.ts
import { parseJSON } from 'date-fns';

const jsonString = '{"date":"2021-10-10T10:10:10.000Z"}';
const parsedDate = parseJSON(jsonString, new Date());

console.log(parsedDate);
// Output: 2021-10-10T10:10:10.000Z
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The parseJSON function takes two arguments: the JSON string to parse, and an optional default date in case the parsing fails. The function returns a Date object if the parsing is successful, otherwise it returns the default date.

In the example above, we pass a valid JSON string and a new Date object as the default value. The function successfully parses the JSON and returns a Date object representing the date and time in the JSON string.

We can also pass a string representation of a Date object as the default value, like this:

index.ts
import { parseJSON } from 'date-fns';

const jsonString = '{"date":"2021-10-10T10:10:10.000Z"}';
const defaultDate = '2021-01-01T00:00:00.000Z';
const parsedDate = parseJSON(jsonString, defaultDate);

console.log(parsedDate);
// Output: 2021-10-10T10:10:10.000Z
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In this example, we pass a string representation of a Date object as the default value. If the parsing fails, the function will return a Date object representing the date and time in the default string.