JS: Loop with multiple conditions

November 17, 2021

I have an array of objects (cars), from which I want to show just the cars which "compete".

const cars = [
  {
    name: "red",
    competes: true,
    category: 1
  },
  {
   name: "blue",
   competes: false,
   category: 1
  },
  {
    name: "green",
    competes: true,
     category: 2
  },
  {
    name: "yellow",
    competes: true,
    category: 3
  }
]

But from those cars which compete, i only want to show those cars which are in category one, which is fine with a for loop.

The objects are now static but since i want to change them in a second moment, i need a code which checks if the cars compete and then checks if there are cars in "category" one.

If there are cars in "category 1", list them
If there are no cars in "category" 1, list those in "category" 2 (but not 3)
And so on

My try was with a loop inside a loop, bit that doesnt work since it displays all multiple times

for (let i = 0; i < cars.length; i++) {
  if (cars[i].competes === false) continue;
  
  for (let f = 0; f < cars.length; f++) {
  if (cars[f].category > 1) break;
  console.log(`Cat1: ${cars[f].name}`);
}
}

How can this be resolved if the "category" attributes inside "cars" are for example all 2 or more?

const cars = [
  {
    name: "red",
    competes: true,
    category: 2
  },
  {
   name: "blue",
   competes: false,
   category: 2
  },
  {
    name: "green",
    competes: true,
     category: 3
  },
  {
    name: "yellow",
    competes: true,
    category: 4
  }
]

>Solution :

First of all you sort the array based on the category and then filter out an array with cars that are gonna compete

const cars = [
    {
        name: "red",
        competes: true,
        category: 1
    },
    {
        name: "blue",
        competes: false,
        category: 1
    },
    {
        name: "green",
        competes: true,
        category: 2
    },
    {
        name: "yellow",
        competes: true,
        category: 3
    }
]
const sorted = cars.sort((a, b) => a.category - b.category);
const compete = sorted.filter(x => x.competes && x.category == sorted[0].category);
console.log(compete[0]);