Lodash _.pullAllBy() Array Method

Posted in lodash Tutorial

Updated on Feb 23, 2024

By Mari Selvan

👁️ 40 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

Efficiently manipulating arrays is a common task in JavaScript development, and Lodash provides a rich set of utility functions to streamline these operations.

One such powerful method is _.pullAllBy(). This method allows developers to remove elements from an array based on a specific property, providing a concise and effective solution for array manipulation.

🧠 Understanding _.pullAllBy()

The _.pullAllBy() method in Lodash is designed to remove elements from an array by comparing a specified property of each element. This can be particularly useful when dealing with arrays of objects and wanting to exclude elements based on a specific property value.

💡 Syntax

syntax.js

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_.pullAllBy(array, values, [iteratee=_.identity])

array: The array to modify.
values: The values to remove.
iteratee: The iteratee invoked per element (default is _.identity).

📝 Example

Let's explore a practical example to illustrate how _.pullAllBy() works:

example.js

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// Include Lodash library (ensure it's installed via npm)
const _ = require('lodash');

const originalArray = [
    { id: 1, name: 'John' },
    { id: 2, name: 'Jane' },
    { id: 3, name: 'Doe' }
];

const valuesToRemove = [
    { id: 1, name: 'John' },
    { id: 3, name: 'Doe' }
];

_.pullAllBy(originalArray, valuesToRemove, 'id');

console.log(originalArray);
// Output: [{ id: 2, name: 'Jane' }]

In this example, _.pullAllBy() removes elements from originalArray where the 'id' property matches any of the 'id' properties in valuesToRemove.

🏆 Best Practices

Specify a Relevant Iteratee:

When using _.pullAllBy(), ensure that the iteratee function is specified appropriately. This function defines the property used for comparison. In the example above, 'id' is used as the iteratee.
example.js
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```
const array = [{ id: 1 }, { id: 2 }, { id: 3 }];
const valuesToRemove = [{ id: 2 }];

_.pullAllBy(array, valuesToRemove, 'id');

console.log(array);
// Output: [{ id: 1 }, { id: 3 }]
```
Understand Property Matching:

Be aware that _.pullAllBy() removes elements based on property matching. Ensure that the properties being compared have the same type and value to achieve the desired result.
example.js
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```
const array = [{ id: 1 }, { id: '1' }, { id: 2 }];
const valuesToRemove = [{ id: '1' }];

_.pullAllBy(array, valuesToRemove, 'id');

console.log(array);
// Output: [{ id: 1 }, { id: 2 }]
```

Validate Input Arrays:

Before applying _.pullAllBy(), validate that both the source array and the values to be removed are valid arrays. Handle edge cases where the input arrays may be empty or undefined.

example.js

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const array = [{ id: 1 }, { id: 2 }, { id: 3 }];
const valuesToRemove = 'not an array';

if (Array.isArray(array) && Array.isArray(valuesToRemove)) {
    _.pullAllBy(array, valuesToRemove, 'id');
    console.log(array);
} else {
    console.error('Invalid input arrays');
}

📚 Use Cases

Filtering Unique Elements:

Use _.pullAllBy() to filter out unique elements from an array of objects based on a specific property.

example.js

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const arrayWithDuplicates = /* ...an array with duplicate objects... */;
const uniqueProperty = 'id';

_.pullAllBy(arrayWithDuplicates, arrayWithDuplicates, uniqueProperty);

console.log(arrayWithDuplicates);

Simplifying Array Differences:

When comparing two arrays of objects and wanting to find the difference based on a specific property, _.pullAllBy() can be a concise solution.

example.js

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const originalData = /* ...an array of objects... */;
const newData = /* ...an updated array of objects... */;
const propertyToCompare = 'id';

_.pullAllBy(originalData, newData, propertyToCompare);

console.log(originalData);

🎉 Conclusion

The _.pullAllBy() method in Lodash is a valuable asset for developers dealing with arrays of objects. It simplifies the process of removing elements based on a specified property, offering a clean and efficient solution. By incorporating this method into your code, you can enhance the manageability and clarity of array manipulation tasks.

Explore the capabilities of _.pullAllBy() and optimize your array operations with Lodash!