Tutorials

Lodash _.pick() Object Method

Posted in lodash Tutorial

Updated on Mar 14, 2024

By Mari Selvan

👁️ 75 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of JavaScript programming, working with objects is a common task. However, dealing with large or complex objects often requires extracting specific properties of interest. This is where the _.pick() method from the Lodash library comes into play.

_.pick() enables developers to select and extract only the desired properties from an object, streamlining data manipulation and enhancing code clarity.

🧠 Understanding _.pick() Method

The _.pick() method in Lodash allows you to extract specified properties from an object, creating a new object with only those properties included. This selective extraction simplifies data handling, reducing complexity and improving readability in your code.

💡 Syntax

The syntax for the _.pick() method is straightforward:

syntax.js

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_.pick(object, [props])

object: The source object from which properties are to be picked.
props: The property names to pick.

📝 Example

Let's dive into a simple example to illustrate the usage of the _.pick() method:

example.js

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const _ = require('lodash');

const sourceObject = {
  name: 'John Doe',
  age: 30,
  email: 'john@example.com',
  isAdmin: true,
};

const pickedProperties = _.pick(sourceObject, ['name', 'email']);

console.log(pickedProperties);
// Output: { name: 'John Doe', email: 'john@example.com' }

In this example, the sourceObject is filtered using _.pick() to create a new object containing only the specified properties.

🏆 Best Practices

When working with the _.pick() method, consider the following best practices:

Specify Target Properties:

Be explicit about which properties you want to extract using _.pick(). This ensures clarity in your code and prevents unintended inclusion or exclusion of properties.

example.js

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const user = {
  name: 'Alice',
  age: 25,
  email: 'alice@example.com',
  isAdmin: false,
};
const filteredUser = _.pick(user, ['name', 'email']);
console.log(filteredUser);
// Output: { name: 'Alice', email: 'alice@example.com' }

Handle Non-existent Properties:

Ensure that the properties you intend to pick exist in the source object. Handling non-existent properties gracefully prevents errors and maintains code robustness.
example.js
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```
const user = {
  name: 'Bob',
  age: 30,
};

const pickedUser = _.pick(user, ['name', 'email']); // 'email' property does not exist

console.log(pickedUser);
// Output: { name: 'Bob' }
```
Avoid Mutating Source Object:

Remember that _.pick() does not modify the source object; it creates a new object with the selected properties. Avoid relying on side effects and ensure that your source object remains unchanged.
example.js
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```
const originalObject = {
  prop1: 'value1',
  prop2: 'value2',
};

const pickedObject = _.pick(originalObject, ['prop1']);

console.log(originalObject);
// Output: { prop1: 'value1', prop2: 'value2' }
```

📚 Use Cases

Data Filtering:

_.pick() is invaluable for filtering out unnecessary data properties, especially when dealing with large or nested objects. This streamlines data processing and optimizes memory usage.

example.js

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const userData = {
  id: '123',
  name: 'John Doe',
  email: 'john@example.com',
  password: 'hashedpassword',
  isAdmin: true,
  // Other properties...
};

const filteredUserData = _.pick(userData, ['id', 'name', 'email']);

console.log(filteredUserData);

Object Transformation:

When transforming objects for specific purposes, _.pick() allows you to select only the relevant properties, simplifying the transformation process and improving code maintainability.

example.js

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const rawApiResponse = {
  status: 'success',
  data: {
    id: '456',
    name: 'Jane Doe',
    email: 'jane@example.com',
    // Other properties...
  },
};

const transformedResponse = {
  status: rawApiResponse.status,
  userData: _.pick(rawApiResponse.data, ['id', 'name', 'email']),
};

console.log(transformedResponse);

API Responses:

In API development, _.pick() can be used to tailor response objects, sending only the necessary data to clients. This reduces bandwidth usage and enhances API performance.

example.js

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app.get('/user/:id', (req, res) => {
  const userId = req.params.id;
  const user = /* ...fetch user data from database or elsewhere... */;

  const responseData = _.pick(user, ['id', 'name', 'email']);
  res.json(responseData);
});

🎉 Conclusion

The _.pick() method in Lodash provides a convenient solution for extracting specific properties from objects in JavaScript. Whether you're filtering data, transforming objects, or customizing API responses, _.pick() empowers you to efficiently manipulate object data with precision and clarity.

By adhering to best practices and exploring diverse use cases, you can harness the full potential of the _.pick() method in your Lodash projects.