Basic Data Structures - Check if an Object has a Property

JavaScript
1

Tell us what’s happening:
Describe your issue in detail here.

Instead of using userObj.hasOwnProperty(“Alan”) I tried solving the problem with in keyword. Is there a way to make it work? It returns true on console.log

Your code so far

let users = {
  Alan: {
    age: 27,
    online: true
  },
  Jeff: {
    age: 32,
    online: true
  },
  Sarah: {
    age: 48,
    online: true
  },
  Ryan: {
    age: 19,
    online: true
  }
};

function isEveryoneHere(userObj) {
  return 'Alan' && 'Jeff' && 'Sarah' && 'Ryan' in userObj;
}

console.log(isEveryoneHere(users));

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Challenge: Basic Data Structures - Check if an Object has a Property

Link to the challenge:
https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-data-structures/check-if-an-object-has-a-property`Preformatted text`

2 
console.log('Alan' && 'Jeff' && 'Sarah' && 'Ryan') // returns 'Ryan'

In other words, your line only check for presence of ‘Ryan’ inside obj.

Yes, you can use 'in' keyword to check the properties individually, and chain the True/False decision with Logical Operators such as && or ||

'Alan' in userObj
'Alan' in userObj && 'Jeff' in userObj 
'Alan' in userObj || 'Jeff' in userObj

About logical operator, you can read more here >>> JavaScript Operators

3

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