JSFiddle - React, Tailwind, and code Playground

JavaScript

var foo = function(){};
alert( 'foo is a Function: ' + (foo instanceof Function) );
alert( 'foo.prototype is an Object: ' + (foo.prototype instanceof Object) );

var blah = new foo();

alert( 'blah is a function: ' + (blah instanceof foo) );
alert( 'blah is not foo: ' + (blah === foo) );