const

The keyword const is a little misleading.

It does not define a constant value. It defines a constant reference to a value.

Because of this you can NOT:

• Reassign a constant value
• Reassign a constant array
• Reassign a constant object

But you CAN:

• Change the elements of constant array
• Change the properties of constant object

// You can create a constant array:  
const cars = ["Saab", "Volvo", "BMW"];  
  
// You can change an element:  
cars[0] = "Toyota";  
  
// You can add an element:  
cars.push("Audi");

structuredClone()

structuredClone() is a built-in JavaScript function that creates a deep copy of a value, allowing for the cloning of complex data types like objects, arrays, and even certain built-in types such as Map and Set. It does not support cloning functions or DOM nodes, and it was introduced to provide a more reliable alternative to JSON-based cloning methods.

const ironman = {
	firstName: 'Tony',
	lastName: 'Stark',
	age: 45,
	address: {
		city: 'New York'
	}
}
// It´s not a deep clone and works just a first level
const spiderMan = {... iroman};

const ironman = {
	firstName: 'Tony',
	lastName: 'Stark',
	age: 45,
	address: {
		city: 'New York'
	}
}
// Creates a deep clone, includes object address
const spiderMan = structuredClone(ironman);