check if key exist 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: js check if object key exists
var obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!