Lodash _.unzipWith() Array Method

Posted in lodash Tutorial

Updated on Apr 07, 2024

By Mari Selvan

👁️ 35 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

Array manipulation in JavaScript often involves dealing with data in various formats. Lodash, a powerful utility library, provides developers with tools to streamline these tasks. Among its array manipulation arsenal is the _.unzipWith() method, designed to transpose and combine arrays using a custom function.

This method offers flexibility and control, making it a valuable asset for developers working with diverse datasets.

🧠 Understanding _.unzipWith()

The _.unzipWith() method in Lodash is designed to transform arrays by combining them based on a provided function. It works in tandem with _.zipWith(), allowing developers to unzip arrays back to their original structure using a custom iteratee function.

💡 Syntax

syntax.js

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_.unzipWith(arrays, [iteratee])

arrays: The array of arrays to process.
iteratee: The function invoked per iteration.

📝 Example

Let's delve into a practical example to understand the functionality of _.unzipWith():

example.js

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const _ = require('lodash');

const zippedArray = [[1, 4], [2, 5], [3, 6]];
const combinedArray = _.unzipWith(zippedArray, _.add);

console.log(combinedArray);
// Output: [6, 15]

In this example, the zippedArray is processed by _.unzipWith(), combining the subarrays using the addition function (_.add), resulting in a new array.

🏆 Best Practices

Understanding Zipped Arrays:

Ensure that you are working with zipped arrays when using _.unzipWith(). Zipped arrays are typically obtained by using _.zipWith().

example.js

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const array1 = [1, 2, 3];
const array2 = ['a', 'b', 'c'];
const zippedArray = _.zipWith(array1, array2, _.concat);

console.log(zippedArray);
// Output: [[1, 'a'], [2, 'b'], [3, 'c']]

Custom Iteration Function:

Take advantage of the iteratee parameter to define a custom function that determines how the values should be combined during the unzipping process.
example.js
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```
const customIteratee = (value1, value2) => value1 * value2;
const multipliedArray = _.unzipWith(zippedArray, customIteratee);

console.log(multipliedArray);
// Output: [1, 4, 9]
```
Handle Unequal Array Lengths:

Be aware that if the zipped arrays have different lengths, the resulting array will have a length equal to the shortest zipped array. Handle unequal array lengths according to your specific use case.
example.js
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```
const unevenZippedArray = [[1, 'a'], [2, 'b', '!'], [3, 'c']];
const combinedUnevenArray = _.unzipWith(unevenZippedArray, _.concat);

console.log(combinedUnevenArray);
// Output: [1, 'a', 2, 'b', 3, 'c']
```

📚 Use Cases

Data Transformation:

_.unzipWith() is useful for transforming data, especially when dealing with arrays that represent different aspects of the same entities.

example.js

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const dataArrays = [
    [1, 'John', true],
    [2, 'Jane', false],
    [3, 'Doe', true],
];

const transformedData = _.unzipWith(dataArrays, (id, name, isActive) => ({ id, name, isActive }));

console.log(transformedData);
// Output: [{ id: 1, name: 'John', isActive: true }, { id: 2, name: 'Jane', isActive: false }, { id: 3, name: 'Doe', isActive: true }]

Custom Aggregation:

When you need to aggregate values from different arrays using a custom logic, _.unzipWith() allows you to specify the aggregation function.

example.js

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const salesData = [[100, 150, 200], [120, 170, 210], [90, 130, 180]];
const totalSales = _.unzipWith(salesData, _.sum);

console.log(totalSales);
// Output: [310, 450, 590]

Dynamic Array Manipulation:

For scenarios where array structures are dynamic and need to be combined or transformed on-the-fly, _.unzipWith() offers a versatile solution.

example.js

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const dynamicArrays = /* ...fetch arrays dynamically... */;
const combinedDynamicArray = _.unzipWith(dynamicArrays, (value1, value2) => value1.concat(value2));

console.log(combinedDynamicArray);

🎉 Conclusion

The _.unzipWith() method in Lodash provides a flexible and powerful mechanism for combining and transforming arrays based on a custom iteratee function. Whether you're dealing with zipped arrays, need to handle unequal lengths, or want to perform dynamic array manipulations, _.unzipWith() empowers you to tailor your data manipulation according to your specific needs.

Explore the capabilities of _.unzipWith() and enhance your array manipulation toolkit in JavaScript!