var element = {}, cart = [];

element.id = id;

element.quantity = quantity;

cart.push({element: element});

// Create an empty object

const myObject = {};

​

// Add a new entry to the object

myObject.newEntry = "This is a new entry";

​

// You can also use square brackets to add a new entry with a dynamic property name

const dynamicPropertyName = "anotherEntry";

myObject[dynamicPropertyName] = "This is another new entry";

​

// Now, you can access these entries

console.log(myObject.newEntry);       // Output: "This is a new entry"

console.log(myObject.anotherEntry);   // Output: "This is another new entry"

​