On gists

Closure (Counter)

JavaScript

closure.js Raw #

function counter() {
  let count = 0;

  return function() {
    count++;
    console.log(count);
  };
}

const increment = counter();
increment(); // Output: 1
increment(); // Output: 2

// OR
function createCounter() {
  let count = 0;

  return {
    increment: function() {
      count++;
    },
    decrement: function() {
      count--;
    },
    getCount: function() {
      return count;
    }
  };
}

const counter = createCounter();
counter.increment();
console.log(counter.getCount()); // Output: 1