object has key javascript 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: javascript hasownproperty

var person = {	
  	"first_name": "Bob",
	"last_name": "Dylan"
};
person.hasOwnProperty('first_name'); //returns true
person.hasOwnProperty('age'); //returns false

Example 3: js check if object has property

const object1 = new Object();
object1.property1 = 42;

console.log(object1.hasOwnProperty('property1'));
// expected output: true

Example 4: js object contain key

if ('key' in myObj)
// better
if (!myObj.hasOwnProperty('key'))

Example 5: typescript check if object has key

if ('key' in myObj)

Example 6: hasOwnProperty

The hasOwnProperty() method returns a boolean indicating whether the object has the specified property as its own property (as opposed to inheriting it).

const object1 = {};
object1.property1 = 42;

console.log(object1.hasOwnProperty('property1'));
// expected output: true

console.log(object1.hasOwnProperty('toString'));
// expected output: false