how to check if an object has a property code example

Example 1: how to check wether the property exist in a object in java script

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

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: javascript does object have property

var person = {'first_name': 'bill','age':20};

if ( person.hasOwnProperty('first_name') ) {
    //person has a first_name property
}