check if key exist in object javascript code example

Example 1: javascript does key exist

var person={"name":"Billy","age":20}
person.hasOwnProperty("name"); // true
person.hasOwnProperty("sex"); // false

Example 2: how to check if object has key javascript

myObj.hasOwnProperty('key') // it checks object for particular key and not on prototype

Example 3: check if a key exists in an object javascript

"key" in obj // true, regardless of the actual value

Example 4: javascript if object has key

if('key' in object)