You should iterate over the elements of the data array and print to the console the number of values in the array that are not NaN in Javasacript

So here is my solution:

let data = [11, null, NaN, 'Hello', 24]

let check = 0;

for (item in data) {
  if (isNaN(item) == false) {
    check +=1
  };
};

console.log(check);

How ever the answer comes five, even though it is 2. I believe isNaN() function gives true or false, so why is it not working?