Remove original and duplicate from an array of objects - JS

Question

I have an array of objects.

const arr = [
  { title: \"sky\", artist: \"Jon\", id: 1 },
  { title: \"rain\", artist: \"Paul\", id: 2 },
  { title: \"sky\", artis         


        

Answer 1

You could run the array through reduce() and then use some to see if you should add if it does not exist, or remove using filter if it does.

Snippet:

const arr = [
  { title: "sky", artist: "Jon", id: 1  },
  { title: "rain", artist: "Paul", id: 2  },
  { title: "sky", artist: "Jon", id: 1  },
  { title: "rain", artist: "Paul", id: 2  },
  { title: "earth", artist: "Frank", id: 3  },
];

const unique = arr.reduce((accumulator, currentValue) => { 
  // add if we don't have
  if (!accumulator.some(x => x.id === currentValue.id)) {
    accumulator.push(currentValue);
  } else {
    // remove if we do
    accumulator = accumulator.filter(x => x.id !== currentValue.id);
  }
  
  return accumulator;
}, []); 

console.info(unique);