In JavaScript, adding new key-value pairs to an object is a common task. There are a few different ways to achieve this, depending on the specific requirements of your application. Let's explore some of the most common methods for pushing keys into objects in JavaScript.

Method 1: Using Dot Notation

One of the simplest ways to add a new key-value pair to an object is by using dot notation. This method is best suited for cases where you know the key name at the time of writing the code. Here's an example:

const myObject = {};

myObject.key1 = 'value1';

myObject.key2 = 'value2';

In this example, we declare an empty object called myObject and then use dot notation to push keys ('key1' and 'key2') with their corresponding values into the object.

Method 2: Using Square Brackets

If the key names are not known at the time of writing the code or are dynamically generated, you can use square brackets to push keys into an object. This method allows you to use variables or expressions to define the key names. Here's an example:

const myObject = {};

const key = 'dynamicKey';

myObject[key] = 'dynamicValue';

In this example, we use a variable key to dynamically define the key name and then push the key-value pair into the object using square brackets notation.

Method 3: Using Object.assign

Object.assign is a built-in method for copying the values of all enumerable own properties from one or more source objects to a target object. It can also be used to push new key-value pairs into an object. Here's an example:

const myObject = {key1: 'value1'};

const newKeys = {key2: 'value2', key3: 'value3'};

Object.assign(myObject, newKeys);

In this example, we use Object.assign to push the new key-value pairs from the newKeys object into the myObject.

No matter which method you choose, pushing keys into objects in JavaScript is a fundamental skill for any developer. Understanding the different approaches will help you write cleaner and more efficient code for your projects. I hope this guide has been helpful in explaining the various methods for adding new key-value pairs to JavaScript objects.