Answers for "how to know if a property exist in a object"

How to tell if an attribute exists on an object

const user = {
    name: "Sicrano",
    age: 14
}

user.hasOwnProperty('name');       // Retorna true
user.hasOwnProperty('age');        // Retorna true
user.hasOwnProperty('gender');     // Retorna false
user.hasOwnProperty('address');    // Retorna false

how to check wether the property exist in a object in java script

if (obj.hasOwnProperty('prop')) {
    // do something
}