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

To use the isFunction function from the Underscore library in TypeScript, you will first need to include the Underscore library in your project using a method such as npm. Here is an example of how to install Underscore using npm:

index.ts
npm install underscore
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Next, you will need to import the Underscore library and the isFunction function into your TypeScript file:

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

const { isFunction } = _;
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Finally, you can use the isFunction function to check if a variable is a function by calling it with the variable as an argument:

index.ts
const myFunction = () => console.log('Hello World');

console.log(isFunction(myFunction)); // true
console.log(isFunction('Hello World')); // false
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By default, TypeScript does not have type definitions for the Underscore library. To get type definitions, you can install the @types/underscore package from npm:

index.ts
npm install @types/underscore
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With the type definitions installed, you can add a reference to them at the top of your TypeScript file:

index.ts
/// <reference types="underscore" />
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This will enable TypeScript to properly check the types of variables and functions that use the Underscore library.