Check Given Property is Own Property of an Object in Javascript

You can check the given property is an own property of an object. You can use the hasOwnProperty() of the object

function Product(name){
    this.name=name
}

Product.prototype.price=1
Product.prototype.getDiscount=function(){
    return this.price*5/100
}

var product= new Product('Fanta')

console.log("name is a property of product "+product.hasOwnProperty("name"))
console.log("price is a property of product "+product.hasOwnProperty("price"))

You can have the following output
>name is a property of product true
>price is a property of product false