add 2620

Author: fishercoder1534

Diff for: javascript/_2620.js

@@ -0,0 +1,18 @@
+/**
+ * @param {number} n
+ * @return {Function} counter
+ */
+var createCounter = function (n) {
+    let counter = n;
+
+    return function () {
+        return n++;
+    };
+};
+
+/**
+ * const counter = createCounter(10)
+ * counter() // 10
+ * counter() // 11
+ * counter() // 12
+ */

Diff for: paginated_contents/javascript/README.md

@@ -1,4 +1,5 @@
 | #    | Title                                                                                                                                                                                      | Solutions                                                                           | Video                                | Difficulty                               | Tag                                                                  
 |------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------|--------------------------------------|------------------------------------------|----------------------------------------------------------------------
 | 2703 | [Return Length of Arguments Passed](https://leetcode.com/problems/return-length-of-arguments-passed/)                                                                                                            | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/javascript/_2703.js) |                                      | Easy                                     | Javascript
+| 2620 | [Counter](https://leetcode.com/problems/counter/)                                                                                                            | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/javascript/_2620.js) |                                      | Easy                                     | Javascript
 | 2619 | [Array Prototype Last](https://leetcode.com/problems/array-prototype-last/)                                                                                                            | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/javascript/_2619.js) |                                      | Easy                                     | Javascript