.hasOwnProperty("code") code example
Example 1: javascript hasownproperty
var person = {
"first_name": "Bob",
"last_name": "Dylan"
};
person.hasOwnProperty('first_name');
person.hasOwnProperty('age');
Example 2: hasOwnProperty
The hasOwnProperty() method returns a boolean indicating whether the object has the specified property as its own property (as opposed to inheriting it).
const object1 = {};
object1.property1 = 42;
console.log(object1.hasOwnProperty('property1'));
console.log(object1.hasOwnProperty('toString'));