check if property exists javascript

1const user = {
2    name: "Sicrano",
3    age: 14
4}
5
6user.hasOwnProperty('name');       // Retorna true
7user.hasOwnProperty('age');        // Retorna true
8user.hasOwnProperty('gender');     // Retorna false
9user.hasOwnProperty('address');    // Retorna false

1if (obj.hasOwnProperty('prop')) {
2    // do something
3}

1for (var name in object) {  
2    if (object.hasOwnProperty(name)) { 
3        // do something with name                    
4    }  
5}
6
7// OR
8
9const hero = {
10  name: 'Batman'
11};
12
13hero.hasOwnProperty('name');     // => true
14hero.hasOwnProperty('realName'); // => false

1const hero = {
2  name: 'Batman'
3};
4
5hero.hasOwnProperty('name');     // => true
6hero.hasOwnProperty('realName'); // => false

1var person = {'first_name': 'bill','age':20};
2
3if ( person.hasOwnProperty('first_name') ) {
4    //person has a first_name property
5}
6

1// the coolest way
2const obj = {
3 weather: 'Sunny; 
4}
5
6if('weather' in obj) {
7 // do something 
8}
9
10