ES6 class ES5 Function Constructors
ES6 class basically does the work of defining a new object and appending functions to its prototype. ES5 Function constructors work and look the same but the main difference is observed when the developer uses the Inheritance property.
They can be considered as the syntax base for constructor functions. These can only be executed with the help of a new operator.
ES6 class allows the developers to instantiate objects using the new operator. ES5 function constructors focus on how the objects are instantiated.
They also ensure the developer that this keyword which is basically used inside the class only refers to the object that is being created by the developer. ES5 function constructor focus on implementing the reusable object creation code. Any function can be used as a constructor.
BY Best Interview Question ON 06 Oct 2019