How to import a single lodash function in Javascript

Overview

Lodash is a javascript library utility that makes it easy to work with arrays, numbers, objects, and other javascript primitives. A Lodash function is one of those functions that perform a single operation on our data, like sorting our array or flattening the array.

Syntax

Here, we'll look at how to import a single Lodash function:

const { functionName } = require("lodash");

Parameters

A Lodash function may take a single parameter, a list of parameters, and even a function. The sample parameters of this function are as follows:

const { functionName } = require("lodash");
// single parameter
functionName(params);
// multiple parameters
functionName(param1, param2);
// and even a parameter with a function
functionName(param, doSomething());

Code example

In the code below, we'll import the flattenDeep function from the Lodash to flatten our complex array completely.

index.js
lodash.js
const { flattenDeep } = require("./lodash.js");
const myArray = [
[1,2,3],
4, 5, 6,
[[7], [8], [9]]
];
const myFlatArray = flattenDeep(myArray);
console.log(myFlatArray);

Explanation

Here is the line-by-line explanation of the code above:

  • Line 1: We import the flattenDeep function from the Lodash to flatten our array. This function takes a single parameter, an array that needs to be flattened.
  • Line 3: We define an array that is several levels deep. We want to flatten this array.
  • Line 9: We call the flattenDeep function on the array to make our array 1-dimensional.