code added

Author: Bharat2044

02_counter.js

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+// Question Link: https://leetcode.com/problems/counter/description/?envType=study-plan-v2&envId=30-days-of-javascript
+// Solution Link: https://leetcode.com/problems/counter/solutions/5424085/easy-javascript-solution/
+
+/*
+2620. Counter
+
+Given an integer n, return a counter function. This counter function initially returns n and then returns 1 more than the previous value every subsequent time it is called (n, n + 1, n + 2, etc).
+
+Example 1:
+Input: 
+n = 10 
+["call","call","call"]
+Output: [10,11,12]
+Explanation: 
+counter() = 10 // The first time counter() is called, it returns n.
+counter() = 11 // Returns 1 more than the previous time.
+counter() = 12 // Returns 1 more than the previous time.
+Example 2:
+Input: 
+n = -2
+["call","call","call","call","call"]
+Output: [-2,-1,0,1,2]
+Explanation: counter() initially returns -2. Then increases after each sebsequent call.
+ 
+Constraints:
+-1000 <= n <= 1000
+0 <= calls.length <= 1000
+calls[i] === "call"
+*/
+
+
+/**
+ * @param {number} n
+ * @return {Function} counter
+ */
+var createCounter = function(n) {
+    
+    return function() {
+        
+        return n++;
+    };
+};
+
+/** 
+ * const counter = createCounter(10)
+ * counter() // 10
+ * counter() // 11
+ * counter() // 12
+ */