how to use the differenceby function from the lodash library in typescript

To use the differenceBy function from the Lodash library in TypeScript, you first need to ensure that you have installed Lodash in your project. You can do this by running the following command:

npm install lodash
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Once you have installed Lodash, you can import the differenceBy function in your TypeScript file as follows:

index.ts
import { differenceBy } from 'lodash';
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The differenceBy function computes the difference between two arrays by comparing the results of running a provided function on each element in both arrays.

Here is an example of how you can use the differenceBy function in TypeScript:

index.ts
// Define two arrays of objects
const arr1 = [{ x: 1 }, { x: 2 }, { x: 3 }];
const arr2 = [{ x: 1 }, { x: 2 }];

// Define a function that returns the value to check for equality
const getProp = (obj: { x: number }) => obj.x;

// Use the differenceBy function to find the difference between the two arrays
const diff = differenceBy(arr1, arr2, getProp);

console.log(diff); // Output: [{ x: 3 }]
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In this example, we use the differenceBy function to find the elements in arr1 that are not present in arr2 by comparing their x property. The result is an array containing the object { x: 3 }.