constructor

What is the Object() constructor and when should you use it?

In this video, we will take a look at how to work with the Object() constructor. The Object() constructor creates a new empty object. Here is an example:

new Object()

When you call new Object(), it returns a new object that can be used to store values.

The Object() constructor can be used with or without the new keyword. When called as a function without new, it behaves differently depending on the type of value passed to it. Here’s an example of using the Object() constructor without the new keyword:

const num = 42;
const numObj = Object(num); // Creates an object wrapper for the number
 
console.log(numObj); // 42
console.log(typeof numObj); // "object"

The first console.log will show 42, but it is important to note that this is not a regular number. As you can see in the second console.log, numObj is an object. This is happening because we used the Object() constructor to turn that input of a number into an object.

What happens if we try to pass null or undefined to the Object() constructor?

const newObj = new Object(undefined);
console.log(newObj); // {}

Well, the result will be an empty object. Another use case for the Object() constructor is when you’re working with a value of unknown type and you need to ensure it’s an object. Let’s take a look at the following example:

function toObject(value) {
  if (value === null || value === undefined) {
    return {};
  }
 
  if (typeof value === "object") {
    return value;
  }
 
  return Object(value);
}
 
console.log(toObject(null));
 
console.log(toObject(true));
 
console.log(toObject([1, 2, 3]));

In this example, we have a function called toObject. The second condition will check if the value is a type of object and will return the value if the condition is true. This condition will check for objects as well as arrays since arrays are special types of objects.

If neither of the conditions is true, the function returns Object(value), which converts the input into an object. This works for values like numbers, strings, and booleans

Most of the time you will not be using the Object() constructor to create new objects because you will be using object literal syntax instead (e.g., const objectLiteral = { name: "Beau" }). But it is still good to understand the basics of working with the Object constructor.