Mutable

The difference between objects and primitive values is that we can change objects, whereas primitive values are immutable.

For example:

let myPrimitive = "first value";
myPrimitive = "another value";
// myPrimitive now points to another string.
let myObject = { key: "first value" };
myObject.key = "another value";
// myObject points to the same object.

You can add, modify, or delete properties of an object using the dot notation or the square bracket notation.

let object = {};
object.foo = 'bar'; // Add property 'foo'
object['baz'] = 'qux'; // Add property 'baz'
object.foo = 'quux'; // Modify property 'foo'
delete object.baz; // Delete property 'baz'