How to Get a Subset of a Javascript Object’s Properties

When working with JavaScript objects, there may be times when you need to extract a subset of properties from an object. This can be useful in various scenarios, such as filtering out unnecessary data or creating a new object with a limited set of properties. In this article, we will explore multiple solutions to achieve this task.

1. Using Object Destructuring

One straightforward way to get a subset of properties from a JavaScript object is by using object destructuring. This technique allows you to extract specific properties and assign them to variables.

const originalObject = {
  name: 'John Doe',
  age: 30,
  email: 'johndoe@example.com',
  city: 'New York'
};

const { name, age } = originalObject;

console.log(name); // Output: John Doe
console.log(age); // Output: 30

In the above example, we have an object called originalObject with properties like name, age, email, and city. By using object destructuring, we extract the name and age properties into separate variables.

2. Using the Spread Operator

Another approach to obtaining a subset of properties is by using the spread operator (...). This operator allows us to create a new object by merging properties from multiple objects.

const originalObject = {
  name: 'John Doe',
  age: 30,
  email: 'johndoe@example.com',
  city: 'New York'
};

const { name, age, ...subset } = originalObject;

console.log(subset); // Output: { email: 'johndoe@example.com', city: 'New York' }

In the above example, we use the spread operator to create a new object called subset that contains all properties of originalObject except for name and age.

3. Using the Object.fromEntries() Method

If you are working with modern JavaScript environments that support the Object.fromEntries() method, you can utilize it to create a new object with a subset of properties.

const originalObject = {
  name: 'John Doe',
  age: 30,
  email: 'johndoe@example.com',
  city: 'New York'
};

const subset = Object.fromEntries(
  Object.entries(originalObject).filter(([key]) => key !== 'name')
);

console.log(subset); // Output: { age: 30, email: 'johndoe@example.com', city: 'New York' }

In the above example, we use Object.entries() to convert originalObject into an array of key-value pairs. We then filter out the desired properties (in this case, excluding the name property) and convert the filtered array back into an object using Object.fromEntries().

These are three different approaches to getting a subset of a JavaScript object’s properties. Depending on your specific use case and JavaScript environment, you can choose the method that best suits your needs.