JAVASCRIPT

js instanceof

let literalString = 'This is a literal string';
let stringObject  = new String('String created with constructor');

literalString instanceof String;  // false, string primitive is not a String
stringObject  instanceof String;  // true

literalString instanceof Object;  // false, string primitive is not an Object
stringObject  instanceof Object;  // true

stringObject  instanceof Date;    // false

instanceof javascript

object instanceof constructor

instance of javascript

var instanceOfOperator = nameOfObject instanceof typeOfObject;

instance in javascript

var instanceOfOperator = nameOfObject instanceof typeOfObject;