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

To use the lastDayOfYear function from the date-fns library in TypeScript, you should first install it:

index.ts
npm install date-fns
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Then, you can import the function and use it in your TypeScript code:

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

const date = new Date('2021-12-31');
const lastDay = lastDayOfYear(date);

console.log(lastDay) // output: Fri Dec 31 2021 00:00:00 GMT-0800 (Pacific Standard Time)
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This code will use the lastDayOfYear function to get the last day of the year for the date that is passed in as an argument. The returned value will be a Date object that you can then use in your TypeScript code. You can also pass in a Date object without any arguments to get the last day of the current year.

When writing TypeScript code that uses date-fns functions, it is important to include type definitions for the library. You can install these type definitions with the following command:

index.ts
npm install --save-dev @types/date-fns
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This will allow TypeScript to recognize the functions from date-fns and provide better type checking and IDE assistance.