how to check if object has key code example

Example 1: how to check if object has key javascript

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

Example 2: typescript check if object has key

if ('key' in myObj)

Example 3: js check if object key exists

var obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!