Clean JavaScript Solution
\nvar ParkingSystem = function(big, medium, small) {\n    this.parking = [null, big, medium, small]\n};\n\n/** \n * @param {number} carType\n * @return {boolean
```\nvar ParkingSystem = function(big, medium, small) {\n    this.parking = [null, big, medium, small]\n};\n\n/** \n * @param {number} carType\n * @return {boolean}\n */\nParkingSystem.prototype.addCar = function(carType) {\n    if(this.parking[carType] > 0) {\n        this.parking[carType]--\n        return true    \n    }\n    \n    return false\n};\t\n```
['JavaScript']