fix key-exercise 3

Author: Alaterry8

Sprint-2/1-key-exercises/3-paths.js

@@ -17,6 +17,10 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = "/Users/mitch/cyf";
-const ext = ".txt";
+const dir = filePath.slice(0,lastSlashIndex);
+const ext = filePath.slice(filePath.lastIndexOf(".")+1); 
+// ^^ combination 
+
+console.log(`The dir part of filePath is ${dir}, while ext is ${ext}`)
+
 // https://www.google.com/search?q=slice+mdn