Objects

Everything that is not a primitive value in JavaScript can be considered an object. Even functions are, in fact, specialized objects; their only difference is that they can be invoked. Usually, however, when we use the term Object, we are referring to a plain object that is normally declared as an object literal delimited by curly braces, with a set of key-value pairs within:

const animal = {
  name: 'Duck',
  hobby: 'Paddling'
};

You can also instantiate an object via the Object constructor and then add properties directly:

const animal = new Object();
animal.name = 'Duck';
animal.hobby = 'Paddling';

Even though they are equivalent, it's preferable to use an object literal in most situations as it is simpler to declare and to read, especially if there are many properties. It also has the added benefit of allowing you to create and...