JavaScript get total function

Question

I have two JS functions that return a total number for me based on some properties. It works fine but feels a bit 'clunky'. Would there be a cleaner way of doing this?

getTotalTrucks: function (data) {
    var noOfTrucks = 0;

    if (data.truck1 == "1") {
        noOfTrucks += 1;
    }
    if (data.truck2 == "1") {
        noOfTrucks += 1;
    }
    if (data.truck3 == "1") {
        noOfTrucks += 1;
    }
    if (data.truck4 == "1") {
        noOfTrucks += 1;
    }
    if (data.truck5 == "1") {
        noOfTrucks += 1;
    }

    return noOfTrucks ;
},

getTotalCars: function (data) {
    var noOfCars = 0;

    if (data.car1 == "2") {
        noOfCars += 1;
    }
    if (data.car2 == "2") {
        noOfCars += 1;
    }
    if (data.car3 == "2") {
        noOfCars += 1;
    }
    if (data.car4 == "2") {
        noOfCars += 1;
    }
    if (data.car5 == "2") {
        noOfCars += 1;
    }

    return noOfCars ;
}

Answer 1

As already noticed by @Sumurai8 and @Mike Brant, your data structure is not pretty suitable for what you want to get.

But if for some reason you can't change it, it's even possible to use it as is, with a quite reduced code like this:

function getTotal(data, searchedPrefix, searchedValue) {
  var regex = new RegExp('^' + searchedPrefix + '\\d+$'), total = 0;
  for (prop in data) {
    if (regex.test(prop) && data[prop] == searchedValue) {
      total++;
    }
  }
  return total;
}

var data = {
  truck1: '1',
  truck2: 'xxx',
  truck3: '0',
  truck4: '1',
  car1: 'zzz',
  car8: 2,
  car88: 2,
  car888: 2
};

console.log('truck & "1":', getTotal(data, 'truck', '1'));
console.log('car & 2:', getTotal(data, 'car', 2));

This way, a unique function works for properties beginning with "truck", "car", or anything else, followed by digits only.
It also allows to look for a value which is any string or number.

Answer 2

Magic values

Your code compares to "1" and "2". What are these values supposed to convey? Use constants to signify what they mean.

Data structure

Your data structure is not great for the task you are trying to accomplish. Why not use a list containing car types? Why not at least split the data based on cars and trucks, so you can get away with just using Object.keys(data.cars).length or even a simple reduce?

{
    "cars" : {
         "car1": "2",
         "car2": "0"
    },
    "trucks" : {
         "truck1": "0",
         "truck2": "1"
    }
}

or

{
    "cars": [
        {
            "type": "car1",
            "status": "broken"
        },
        {
            "type": "car2",
            "status": "contains 4 wheels"
        }
    ],
    "trucks": [
        //you get the point
    ]
}