Tutorials

Lodash _.invoke() Object Method

Posted in lodash Tutorial

Updated on Mar 14, 2024

By Mari Selvan

👁️ 26 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of JavaScript programming, working with objects is commonplace. The Lodash library provides a plethora of utility functions to simplify object manipulation, and one such function is _.invoke().

This method allows developers to invoke a specified method on each element of an object, providing a concise and efficient way to perform actions across multiple objects.

🧠 Understanding _.invoke() Method

The _.invoke() method in Lodash enables developers to invoke a specified method on each element of an object. This method accepts two parameters: the object to iterate over and the method to invoke on each element. By leveraging _.invoke(), developers can streamline their code and perform consistent actions across diverse sets of objects.

💡 Syntax

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

syntax.js

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_.invoke(collection, methodName, ...args)

collection: The object or array-like object to iterate over.
methodName: The name of the method to invoke.
...args: Additional arguments to pass to the invoked method.

📝 Example

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

example.js

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const _ = require('lodash');

const myObjects = [
{
  name: 'John',
  greet: function() {
    return `Hello, ${this.name}!`;
  }
},
{
  name: 'Alice',
  greet: function() {
    return `Hi, ${this.name}!`;
  }
},
{
  name: 'Bob',
  greet: function() {
    return `Hey, ${this.name}!`;
  }
}];

const greetings = _.invoke(myObjects, 'greet');

console.log(greetings);
// Output: ['Hello, John!', 'Hi, Alice!', 'Hey, Bob!']

In this example, the greet() method is invoked on each object in the myObjects array using _.invoke(), resulting in an array of greetings.

🏆 Best Practices

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

Ensure Method Existence:

Before using _.invoke(), ensure that the method exists on each object to prevent errors. Missing methods may result in unexpected behavior or runtime errors.

example.js

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const myObjects = [
  {
    name: 'John',
    greet: function() {
      return `Hello, ${this.name}!`;
    }
  },
  {
    name: 'Alice'
  }, // Missing greet method
  {
    name: 'Bob',
    greet: function() {
      return `Hey, ${this.name}!`;
    }
  }
];

const greetings = _.invoke(myObjects, 'greet');

console.log(greetings);
// Output: ['Hello, John!', undefined, 'Hey, Bob!']

Pass Additional Arguments:

Utilize the ...args parameter to pass additional arguments to the invoked method if required. This allows for greater flexibility and customization in method invocation.

example.js

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const myObjects = [
{
  name: 'John',
  greet: function(suffix) {
    return `Hello, ${this.name}${suffix}!`;
  }
},
{
  name: 'Alice',
  greet: function(suffix) {
    return `Hi, ${this.name}${suffix}!`;
  }
},
{
  name: 'Bob',
  greet: function(suffix) {
    return `Hey, ${this.name}${suffix}!`;
  }
}];

const greetings = _.invoke(myObjects, 'greet', ' - How are you');

console.log(greetings);
// Output: ['Hello, John - How are you!', 'Hi, Alice - How are you!', 'Hey, Bob - How are you!']

Consider Performance Implications:

Be mindful of the performance implications when using _.invoke() on large datasets. Iterating over a large number of objects or invoking complex methods may impact performance.
example.js
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```
const largeDataset = /* ...fetch data from API or elsewhere... */;
const results = _.invoke(largeDataset, 'processData');

console.log(results);
```

📚 Use Cases

Batch Processing:

_.invoke() is useful for batch processing operations where the same method needs to be applied to multiple objects. This can streamline workflows and improve code maintainability.
example.js
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```
const users = /* ...fetch user data from database or API... */;
_.invoke(users, 'sendEmailNotification', 'New message!');
```
Dynamic Method Invocation:

In scenarios where the method to be invoked is determined dynamically, _.invoke() provides a convenient solution. This enables dynamic method invocation based on runtime conditions.
example.js
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```
const shapes = /* ...fetch shape objects from data source... */;
const methodToInvoke = userPreference === 'area' ? 'calculateArea' : 'calculatePerimeter';
const results = _.invoke(shapes, methodToInvoke);
```
Object Transformation:

When transforming objects by applying a common operation, such as formatting or validation, _.invoke() can simplify the transformation process and improve code readability.
example.js
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```
const data = /* ...fetch raw data from external source... */;
const transformedData = _.invoke(data, 'transform');
```

🎉 Conclusion

The _.invoke() method in Lodash offers a powerful mechanism for invoking a specified method on each element of an object. Whether you're performing batch processing, dynamic method invocation, or object transformation, _.invoke() provides a versatile and efficient solution for object manipulation in JavaScript.

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