Prototype are link or pointer to other objects. All objects have prototype. Objects are chained together by the prototype chain. //Constructor function Office(name, location, domain) { this.name=name; this.location=location; this.domain=domain; } //Prototype Office.Prototype={ interview: function(){ alert("Hi office location is"+ this.location); } }; var myoffice= new Office("expo-e", "london", "telecommunication"); myoffice.interview; // hi office location is london In the above example myoffice prototype is shared with Office Office prototype is shared with object Object prototype is shared with null myoffice->Office->Object->null, makes the complete chain of prototype. when you lookup a property on an object, it will walk up the prototype chain until its found. First my office is checked then the Office is checked, then object and finally it reaches null.
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