Question 5 solution (findTheScientist)

force-app/main/default/classes/ClassesObjectsMethods.cls

@@ -147,16 +147,18 @@ public with sharing class ClassesObjectsMethods {
         List<String> scientistNames = new List<String>{'Tim Berners-Lee', 'Alan Turing', 'Grace Hopper', 'Donald Knuth', 'Guido van Rossum', 'Ken Thompson', 'Stephen Hawking'};
 
         // The variable to store the concatenated string
-
-        // Loop through the list of scientists' names
-
-            // If the name doesn't contain the letter 'G', skip this iteration
-
-            // Add the name to the result string, followed by a comma
-
-        // Remove the last comma from the result string
-
-        return null; // Replace null with the variable you used to store the result
+        String result='';
+
+        // Loop through the list of scientists' names     
+        for (Integer i=0; i<scientistNames.size(); i++) {
+            if(scientistNames[i].toLowerCase().contains('g')) {
+                result += scientistNames[i];
+                if (i != (scientistNames.size()-1)) {
+                    result += ',';
+                }
+            }    
+        }
+        return result;
     }
 
     /**