2620-Counter.js

/**
 *
 * 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) {
  let count = n;
  return function () {
    return count++;
  };
};

/**
 * const counter = createCounter(10)
 * counter() // 10
 * counter() // 11
 * counter() // 12
 */