day 23 task complete

Author: Sanchitbajaj02

day23/leetcode2631.js

@@ -0,0 +1,24 @@
+// 2631. Group By
+// URL -> https://leetcode.com/problems/group-by
+
+/**
+ * @param {Function} fn
+ * @return {Object}
+ */
+Array.prototype.groupBy = function (fn) {
+  let obj = {};
+
+  for (const item of this) {
+    if (obj[fn(item)]) {
+      obj[fn(item)].push(item);
+    } else {
+      obj[fn(item)] = [item];
+    }
+  }
+
+  return obj
+};
+
+/**
+* [1,2,3].groupBy(String) // {"1":[1],"2":[2],"3":[3]}
+*/