In JavaScript, objects are a fundamental data structure used to store key-value pairs. There are several ways to add new keys to an existing object, and one common method is to use the push function. Here's how to push keys into objects in JavaScript.

To add a new key to an object using the push method, you can follow these steps:

1. Create a new key-value pair as an array.

2. Use the push method to add the new key-value pair to the object.

Let's look at an example:

```javascript

// Create an object

let myObject = {

key1: 'value1',

key2: 'value2'

};

// Create a new key-value pair as an array

let newKeyValuePair = ['key3', 'value3'];

// Use the push method to add the new key-value pair to the object

myObject.push(newKeyValuePair);

console.log(myObject);

// Output: { key1: 'value1', key2: 'value2', '0': 'key3', '1': 'value3' }

```

In this example, we first create an object called `myObject` with two key-value pairs. Then, we create a new key-value pair as an array called `newKeyValuePair`. Finally, we use the push method to add the new key-value pair to the `myObject` object.

It's important to note that the push method does not work directly on objects, as objects do not have a push method. Instead, it is used on arrays. When using the push method to add new keys to objects, the new key-value pair is added as an array element with numerical indexes.

In summary, the push method can be used to add new keys to JavaScript objects by creating a new key-value pair as an array and then using the push method to add the array to the object. This provides a simple and effective way to dynamically add new keys to objects in JavaScript.

In conclusion, the push method is a useful tool for adding new keys to JavaScript objects. By following the steps outlined in this article, you can easily push keys into objects and manipulate their contents as needed. This provides a powerful way to work with objects in JavaScript and enhance the functionality of your code.