Tutorials

Lodash _.functionsIn() Object Method

Posted in lodash Tutorial

Updated on Mar 13, 2024

By Mari Selvan

👁️ 30 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the dynamic world of JavaScript development, effective manipulation of objects is crucial. Lodash, a powerful utility library, comes to the rescue with a variety of functions designed to simplify object handling.

Among these functions, the _.functionsIn() method stands out, providing developers with a convenient way to retrieve all function property names, including inherited ones, from an object.

🧠 Understanding _.functionsIn() Method

The _.functionsIn() method in Lodash is designed to traverse the prototype chain of an object and return an array containing all function property names, including inherited ones. This can be particularly useful when inspecting objects for available methods or functions.

💡 Syntax

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

syntax.js

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_.functionsIn(object)

object: The object to inspect.

📝 Example

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

example.js

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const _ = require('lodash');

function Animal(name) {
  this.name = name;
}

Animal.prototype.sayHello = function() {
  console.log(`Hello, I'm ${this.name}!`);
};

const dog = new Animal('Buddy');
const functionsInDog = _.functionsIn(dog);

console.log(functionsInDog);
// Output: ['sayHello']

In this example, the Animal function is used to create an object (dog), and _.functionsIn() is employed to retrieve all function property names, including the inherited one (sayHello).

🏆 Best Practices

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

Prototype Chain Exploration:

Leverage _.functionsIn() to explore the prototype chain of an object and obtain all function property names, offering a comprehensive view of available methods.

example.js

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class Vehicle {
  drive() {
    console.log('Vehicle is being driven.');
  }
}

class Car extends Vehicle {
  honk() {
    console.log('Honk! Honk!');
  }
}

const myCar = new Car();
const allFunctions = _.functionsIn(myCar);

console.log(allFunctions);
// Output: ['honk', 'drive']

Identifying Inherited Functions:

Use _.functionsIn() to identify functions inherited from the object's prototype, allowing for a clear understanding of the object's capabilities.

example.js

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function Shape() {
  this.area = function() {
    console.log('Calculating area...');
  };
}

function Circle(radius) {
  this.radius = radius;
}
Circle.prototype = new Shape();
const myCircle = new Circle(5);
const inheritedFunctions = _.functionsIn(myCircle);
console.log(inheritedFunctions);
// Output: ['area']

📚 Use Cases

Object Method Inspection:

_.functionsIn() is valuable when inspecting objects, providing a quick and reliable way to retrieve all function property names, including inherited ones.

example.js

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const myObject = {
  greet() {
    console.log('Hello!');
  },
  calculate() {
    console.log('Calculating...');
  },
};

const allMethods = _.functionsIn(myObject);

console.log(allMethods);
// Output: ['greet', 'calculate']

Dynamic Object Analysis:

In scenarios where objects are dynamically constructed or extended, _.functionsIn() facilitates dynamic analysis by capturing all available methods, including those inherited.

example.js

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function BaseObject() {
  this.baseMethod = function() {
    console.log('Base method.');
  };
}

function ExtendedObject() {
  this.extendedMethod = function() {
    console.log('Extended method.');
  };
}

ExtendedObject.prototype = new BaseObject();

const dynamicObject = new ExtendedObject();
const allDynamicMethods = _.functionsIn(dynamicObject);

console.log(allDynamicMethods);
// Output: ['extendedMethod', 'baseMethod']

🎉 Conclusion

The _.functionsIn() method in Lodash proves to be a valuable asset for JavaScript developers, offering an efficient means to inspect objects and retrieve all function property names, including inherited ones. Whether you're exploring object capabilities or dynamically analyzing objects, _.functionsIn() provides a versatile tool for comprehensive object method discovery.

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