how to use the differenceby function from lodash in javascript

The differenceBy() function from lodash is used to find the difference between two arrays by applying a function that converts the values in the arrays before the comparison.

Here's how to use it:

1. First, you need to import the differenceBy() function from lodash. You can do this using ES6 modules like this:

index.tsx
import { differenceBy } from 'lodash';
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or you can use CommonJS modules like this:

index.tsx
const { differenceBy } = require('lodash');
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2. Next, you need to provide the two arrays you want to compare as the first two arguments to the differenceBy() function. For example:

index.tsx
const array1 = [1.2, 2.3, 3.4];
const array2 = [2.5, 3.6, 4.7];

const result = differenceBy(array1, array2);
console.log(result); // [1.2]
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This will find the difference between array1 and array2 by comparing their values without any conversion.

3. If you want to apply a function to the values in the arrays before the comparison, you can pass it as the third argument to the differenceBy() function. For example:

index.tsx
const array1 = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }];
const array2 = [{ 'x': 2 }, { 'x': 3 }, { 'x': 4 }];

const result = differenceBy(array1, array2, 'x');
console.log(result); // [{ 'x': 1 }]
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This will find the difference between array1 and array2 by comparing the x property of the objects in the arrays.

So that's how you can use the differenceBy() function from lodash to find the difference between two arrays with or without applying a function to their values.