给定露营地数组，编写一个返回总和和匹配输入字符串的函数

Question

I have been given a campgrounds array and I need to write a function, countByView() with 2 parameters, (campgrounds, view). I then need to add up the total number of campgrounds with the same view, and return the matching string value for that input.

For example: countByView(campgrounds, 'ocean') //-> 3

Here is the given array:

let campgrounds = [
  { number: 1, view: 'ocean', partySize: 8, isReserved: false },
  { number: 5, view: 'ocean', partySize: 4, isReserved: false },
  { number: 12, view: 'ocean', partySize: 4, isReserved: true },
  { number: 18, view: 'forest', partySize: 4, isReserved: false },
  { number: 23, view: 'forest', partySize: 4, isReserved: true }
];

Here is what I have so far:

    function countByView(campgrounds, view) {
  let ocean = 0;
  let forest = 0;
  let desert = 0;
  
  for (let i = 0; i < campgrounds.length; i++) {
    if (campgrounds.view === 'ocean') {
      ocean++;
    } else if (campgrounds.view === 'forest') {
      forest++;
    } else {
      desert++;
    }
  }
}

I'm not sure if I'm calling the campgrounds.view wrong or it's my counter, or everything

Answer 1

You only need to count the elements with the passed view . Here is a working version:

 let campgrounds = [ { number: 1, view: 'ocean', partySize: 8, isReserved: false }, { number: 5, view: 'ocean', partySize: 4, isReserved: false }, { number: 12, view: 'ocean', partySize: 4, isReserved: true }, { number: 18, view: 'forest', partySize: 4, isReserved: false }, { number: 23, view: 'forest', partySize: 4, isReserved: true } ]; function countByView(campgrounds, view) { let total = 0; for (let i = 0; i < campgrounds.length; i++) { if (campgrounds[i].view === view) { total++; } } return total; } console.log(countByView(campgrounds, 'ocean'));

You can also use .filter to count the matching items:

 let campgrounds = [ { number: 1, view: 'ocean', partySize: 8, isReserved: false }, { number: 5, view: 'ocean', partySize: 4, isReserved: false }, { number: 12, view: 'ocean', partySize: 4, isReserved: true }, { number: 18, view: 'forest', partySize: 4, isReserved: false }, { number: 23, view: 'forest', partySize: 4, isReserved: true } ]; function countByView(campgrounds, view) { return campgrounds.filter(campground => campground.view===view).length; } console.log(countByView(campgrounds, 'ocean'));