fix: corrected guide solutions and explanations (#36125)

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

@@ -3,13 +3,7 @@ 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 users, 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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator) provides a more in depth analysis of the ternary operator.
-
-### Solution-1:
+### Basic Solution:
 ```javascript
 
 let users = {
@@ -32,23 +26,57 @@ let users = {
 };
 
 function isEveryoneHere(obj) {
-  // change code below this line
-  if(users.hasOwnProperty('Alan','Jeff','Sarah','Ryan')) {
+  if (
+    obj.hasOwnProperty('Alan') && obj.hasOwnProperty('Jeff') &&
+    obj.hasOwnProperty('Sarah') && obj.hasOwnProperty('Ryan')
+  ) {
     return true;
   }
   return false;
-  // change code above this line
 }
-
-console.log(isEveryoneHere(users));
-
 ```
 
-### Solution-2:
+#### Code Explanation
+
+* Checks whether object contains all users by using the `hasOwnProperty` method for each name with the `&&` operator to return a `true` or `false` value.
+
+### Advanced Solution:
 ```javascript
+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) {
-  return (users.hasOwnProperty('Alan','Jeff','Sarah','Ryan')) ? true : false;
+  return [
+    'Alan',
+    'Jeff',
+    'Sarah',
+    'Ryan'
+  ].every(name => obj.hasOwnProperty(name));
 }
-
 ```
+
+#### Code Explanation
+
+* Uses an array with all of the names which should be present in the object.
+* The `every` method is used to validate all of names used in conjunction with the `hasOwnProperty` method result in a value of `true` being returned during each iteration.
+* If at least one name is not found using the `hasOwnProperty` method, the `every` method returns `false`.
+
+#### Relevant Links
+
+* [Array.prototype.every](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every)