Check if an Object has a Property - Wrong Code in Hint Section

JavaScript
1

`
Found a tiny mistake in the hint section of this challenge.

function isEveryoneHere(obj) {
// change code below this line
if(users.hasOwnProperty(‘Alan’,‘Jeff’,‘Sarah’,‘Ryan’)) {
return true;
}
return false;
// change code above this line
}

Instead of
if(users.hasOwnProperty(‘Alan’,‘Jeff’,‘Sarah’,‘Ryan’)) {
return true;
}
Correct code should be
if(obj.hasOwnProperty(‘Alan’,‘Jeff’,‘Sarah’,‘Ryan’)) {
return true;
}

Same for Solution-2.

function isEveryoneHere(obj) {
return (obj.hasOwnProperty(‘Alan’,‘Jeff’,‘Sarah’,‘Ryan’)) ? true : false;
}
`

2

Yeah, that’s totally wrong – thank you for picking up on it. I think it has been fixed, but at the minute the fix isn’t live, hopefully should be soon!

3

checking property exist in object or not

var person = {

name: 'amal'

};

console.log(person.hasOwnProperty('name'));

it will produce result as true

As you know object has property and value.
this hasOwnProperty is a method which is used to check whether the property
is there or not . it can not use for checking the value of object . it will return either true or false.
it can only one argument at a time

How to check whether property exist or not if that is the collection of many object stored in an array ?

var person = {[

name: 'amal'
],
[

name: 'John'
],[

name: 'amal',age:50
],
};

now if you want to know whether property is stored in an object you have to provide index of the array where that specific object is stored

console.log(person[1].hasOwnProperty('name')) => true
console.log(person[1].hasOwnProperty('age')) => false
console.log(person[2].hasOwnProperty('age')) => true
4
5

Just to be clear, hasOwnProperty only takes one argument.

6

Hi, thank you for this but there is a syntax mistake in the hint for that challenge, that’s what the OP was talking about, they weren’t asking how to use the hasOwnProperty function.

7

Sry I did not check the challenge. I only tried to explain hasOwnProperty method

1 Like