Answers for "how to check if the property exists in an object javascript"

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

javascript check if object property exists

var person = {'first_name': 'bill','age':20};

if ( person.hasOwnProperty('first_name') ) {
    //person has a first_name property
}