Lodash _.xorBy() Array Method

Posted in lodash Tutorial

Updated on Feb 24, 2024

By Mari Selvan

👁️ 52 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of JavaScript development, manipulating arrays efficiently is a common challenge. Lodash, a comprehensive utility library, provides an arsenal of functions to simplify these tasks. One such function is _.xorBy(), a method designed to compute the symmetric difference of arrays based on a custom iteratee function.

This method enhances the process of array comparison, making it a valuable tool for developers dealing with complex data structures.

🧠 Understanding _.xorBy()

The _.xorBy() method in Lodash is employed to obtain the symmetric difference of arrays based on a provided iteratee function. This iteratee function allows developers to define custom criteria for comparing elements, providing flexibility in array manipulation.

💡 Syntax

syntax.js

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_.xorBy([arrays], iteratee)

arrays: The arrays to inspect.
iteratee: The function invoked per iteration.

📝 Example

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

example.js

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const _ = require('lodash');

const array1 = [1, 2, 3];
const array2 = [2, 3, 4];
const customIteratee = value => value % 2;

const symmetricDifference = _.xorBy(array1, array2, customIteratee);

console.log(symmetricDifference);
// Output: [1, 4]

In this example, the symmetric difference of array1 and array2 is computed based on the custom criteria defined by the customIteratee function.

🏆 Best Practices

Understanding Symmetric Difference:

Grasp the concept of symmetric difference in set theory to fully utilize _.xorBy(). Symmetric difference represents elements that are present in either of the arrays, but not in both.
example.js
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```
const setA = [1, 2, 3];
const setB = [2, 3, 4];

const symmetricDifferenceAB = _.xorBy(setA, setB);

console.log(symmetricDifferenceAB);
// Output: [1, 4]
```

Define Custom Criteria:

Leverage the power of custom criteria by utilizing the iteratee function. This allows you to tailor the comparison logic to specific attributes or conditions.

example.js

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const arrayA = [{ id: 1, name: 'apple' }, { id: 2, name: 'banana' }];
const arrayB = [{ id: 2, name: 'banana' }, { id: 3, name: 'orange' }];

const customCriteria = obj => obj.name;

const symmetricDifferenceObjects = _.xorBy(arrayA, arrayB, customCriteria);

console.log(symmetricDifferenceObjects);
// Output: [{ id: 1, name: 'apple' }, { id: 3, name: 'orange' }]

Input Validation:

Ensure the input arrays are valid before applying _.xorBy(). This includes checking for the presence of arrays and confirming that the iteratee function is specified.
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```
const invalidArrays = _.xorBy(undefined, null, value => value);

console.log(invalidArrays);
// Output: []
```

📚 Use Cases

Finding Unique Elements:

Identify unique elements across multiple arrays using _.xorBy(). This is particularly useful when dealing with datasets containing duplicate values.
example.js
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```
const dataset1 = [1, 2, 3, 4];
const dataset2 = [3, 4, 5, 6];
const uniqueValues = _.xorBy(dataset1, dataset2);

console.log(uniqueValues);
// Output: [1, 2, 5, 6]
```

Handling Array Differences in Objects:

When working with arrays of objects, _.xorBy() can be applied to find objects with distinct attributes based on a custom criteria.

example.js

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const arraySet1 = [{ id: 1, name: 'apple' }, { id: 2, name: 'banana' }];
const arraySet2 = [{ id: 2, name: 'banana' }, { id: 3, name: 'orange' }];

const uniqueObjects = _.xorBy(arraySet1, arraySet2, obj => obj.name);

console.log(uniqueObjects);
// Output: [{ id: 1, name: 'apple' }, { id: 3, name: 'orange' }]

Symmetric Difference with Custom Logic:

Employ _.xorBy() to find the symmetric difference based on a custom logic or attribute of the elements.

example.js

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const setX = [1, 2, 3, 4, 5];
const setY = [4, 5, 6, 7, 8];

const symmetricDifferenceCustomLogic = _.xorBy(setX, setY, value => value % 2);

console.log(symmetricDifferenceCustomLogic);
// Output: [1, 2, 6, 7, 8]

🎉 Conclusion

The _.xorBy() method in Lodash provides a powerful solution for computing the symmetric difference of arrays based on a custom iteratee function. Whether you're working with simple datasets or complex data structures, this method offers a versatile tool for array manipulation in JavaScript.

Unlock the potential of array comparison with _.xorBy() and enhance your JavaScript development experience!