Counter - LeetCode: 30 Days of JavaScript

Welcome to day two LeetCode challenge in the "30 Days of JavaScript" series. We will be solving this problem:

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).

Problem breakdown

We are expected to:

1. Write a function that takes an integer n.

2. The function should return a counter function.

3. The counter function will initially return n , increase by 1 each time the function is called, and then, return the incremented value on the next call. For example, if 2 is the initial value, each time you call the counter function, it will return 3, 4, 5, 6, and so on.

Solution

// 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).
var createCounter = function (n) {
  return function () {
    const sum = n++;
    return sum;
  };
};

const aggregate = createCounter(5);
//console.log(aggregate()); //6
//console.log(aggregate()); // 7
//console.log(aggregate()); // 8

From the code above, we created a function called createCounter that takes an integer n. createCounter returns an anonymous function that does not take any parameter. The returned function will increment the value of n using the post-increment operator('n++') and then, return the value of n.

Furthermore, we assigned createCounter to a variable called aggregate, and n is given the value of 5. So each time aggregate is called, n increases by 1.

Conclusion

This article solved the second LeetCode challenge in the "30 Days of JavaScript" series. I look forward to solving the next challenge.