When working with JavaScript objects, it's common to need to push new key-value pairs into the object. There are a few different ways to accomplish this, depending on the specific requirements of your code. Here are three common methods for pushing keys into an object.

1. Dot notation: The simplest way to add a new key to an object is by using dot notation. For example, if you have an object called 'myObject' and you want to add a new key 'newKey' with the value 'newValue', you can do so with the following code: myObject.newKey = 'newValue'; This method is straightforward and works well for adding a single key at a time.

2. Bracket notation: If you need to add a key to an object dynamically, based on a variable or some other condition, you can use bracket notation. For example, if you have a variable 'newKey' containing the name of the key you want to add, you can use the following code: myObject[newKey] = 'newValue'; This method is especially useful when the key you want to add is not known in advance, or when you need to add multiple keys at once.

3. Object.assign(): Another approach to pushing keys into an object is by using the Object.assign() method. This method is helpful when you want to merge multiple objects together, or add multiple keys at once. Here's an example of how to use Object.assign() to add new keys to an object: const myObject = { existingKey: 'existingValue' }; const newKeys = { newKey1: 'value1', newKey2: 'value2' }; Object.assign(myObject, newKeys); In this example, the new keys 'newKey1' and 'newKey2' and their values are added to the 'myObject' object.

By using these methods, you can effectively push keys into an object in JavaScript, whether you need to add a single key or multiple keys at once. It's important to choose the method that best fits your specific use case, taking into consideration the dynamic nature of your keys and the structure of your objects.