freeCodeCamp/guide/english/certifications/javascript-algorithms-and-data-structures/basic-data-structures/check-if-an-object-has-a-property/index.md

title
Check if an Object has a Property

Check if an Object has a Property

Method:

• The simplest way to complete this challenge is to create an ìf-statement to check wether or not the object contains all useres, then to return a true or false statement. The first solution does just this.
• The second solution works in exactly the same way, only it uses 1 line of code - Conditional(ternary)-Operator - within the function.

developer.mozilla.org provides a more in depth analysis of the ternary operator.

Solution-1:

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

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

console.log(isEveryoneHere(users));

Solution-2:

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