diff --git a/projects/007-run-length-encoding/js/index.js b/projects/007-run-length-encoding/js/index.js
index e69de29..d3de283 100644
--- a/projects/007-run-length-encoding/js/index.js
+++ b/projects/007-run-length-encoding/js/index.js
@@ -0,0 +1,23 @@
+const prompt = require('prompt-sync')();
+
+/**
+ *
+ * @param {array} decompressedList
+ * @returns A function that maps each individual element of the array and counts how many duplicates there are.
+ */
+function compressedList(decompressedList) {
+    if (!decompressedList) return []; // Base case: empty array
+
+    const compressedArray = []; // Empty array to insert each repeated element
+
+    decompressedList.forEach(
+        (item) => (compressedArray[item] = (compressedArray[item] || 0) + 1)
+    ); // Recursive step
+
+    return compressedArray;
+}
+
+const decompressedList = [...prompt('Enter what you desire')].sort();
+// Transformed the message typed by the user into an array and arranged each character alphabetically
+
+console.log(compressedList(decompressedList));