how to use the default function from the underscore library in typescript

To use the default function from the Underscore library in TypeScript, you first need to install the Underscore library through a package manager such as npm:

index.ts
npm install underscore
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Once you have installed the Underscore library, you can then import it and call its default function:

index.ts
import * as _ from 'underscore';

const numbers = [1, 2, 3, 4, 5];
const evenNumbers = _.filter(numbers, num => num % 2 === 0);

console.log(evenNumbers); // [2, 4]
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In this example, we are importing the Underscore library and calling its filter function to filter out even numbers from an array of numbers. The result is then logged to the console.

Note that in TypeScript, we are using the wildcard * to import all the functions from the Underscore library into a single variable _. This allows us to call any function from the library using the _ variable, without having to import each function separately.