Intermediate Algorithm Scripting: Diff Two Arrays

Intermediate Algorithm Scripting: Diff Two Arrays.js

function diffArray(arr1, arr2) {

  let first = checkOnce(arr1, arr2);
  let second = checkOnce(arr2, arr1);
  
  return first.concat(second);
}

function checkOnce(arr1, arr2){
  let unique = [];
  arr1.every(item=>{
    if(!arr2.some(innerItem=> {
      if(innerItem == item)
        return true;
      else
        return false;
        })){
      unique.push(item);
    }
    return true;
  });
  return unique;
}

diffArray(["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]);