tally function updated to create empty object with no inherited properties

Author: zilinskyte

Sprint-2/implement/tally.js

@@ -2,17 +2,16 @@ function tally(items) {
   if (!Array.isArray(items)) {
     throw new Error("Input must be an array");
   }
-  const counts = {}; // empty object to store tally of key-value pairs
+  const counts = Object.create(null); // empty object to store tally of key-value pairs
+  // object.create(null) creates a new object with no inherited properties
   for (const item of items) {
-    // iterates through each element in the items array
-    if (counts[item]) {
-      // checks if the item already exists as a key in counts object
-      counts[item] += 1; // increments the count for that item by 1
-    } else {
-      counts[item] = 1; // initializes the count for that item to 1
-    }
+    // iterate through each item in the input array
+    const key = String(item); // convert item to string to use as key
+    counts[key] = (counts[key] || 0) + 1; // increment count for this key
   }
   return counts; // returns the final counts object
 }
 
 module.exports = tally;
+
+console.log(tally(["toString", "toString"]));