How to get the difference between two arrays of objects in JavaScript

Question

I have two result sets like this:

// Result 1
[
    { value: "0", display: "Jamsheer" },
    { value: "1", display: "Muhammed" },
    { value: "2", display: "Ravi" },
    { value: "3", display: "Ajmal" },
    { value: "4", display: "Ryan" }
]

// Result 2
[
    { value: "0", display: "Jamsheer" },
    { value: "1", display: "Muhammed" },
    { value: "2", display: "Ravi" },
    { value: "3", display: "Ajmal" },
]

The final result I need is the difference between these arrays – the final result should be like this:

[{ value: "4", display: "Ryan" }]

Is it possible to do something like this in JavaScript?

Answer 1

Using only native JS, something like this will work:

a = [{ value:"4a55eff3-1e0d-4a81-9105-3ddd7521d642", display:"Jamsheer"}, { value:"644838b3-604d-4899-8b78-09e4799f586f", display:"Muhammed"}, { value:"b6ee537a-375c-45bd-b9d4-4dd84a75041d", display:"Ravi"}, { value:"e97339e1-939d-47ab-974c-1b68c9cfb536", display:"Ajmal"},  { value:"a63a6f77-c637-454e-abf2-dfb9b543af6c", display:"Ryan"}]
b = [{ value:"4a55eff3-1e0d-4a81-9105-3ddd7521d642", display:"Jamsheer", $$hashKey:"008"}, { value:"644838b3-604d-4899-8b78-09e4799f586f", display:"Muhammed", $$hashKey:"009"}, { value:"b6ee537a-375c-45bd-b9d4-4dd84a75041d", display:"Ravi", $$hashKey:"00A"}, { value:"e97339e1-939d-47ab-974c-1b68c9cfb536", display:"Ajmal", $$hashKey:"00B"}]

function comparer(otherArray){
  return function(current){
    return otherArray.filter(function(other){
      return other.value == current.value && other.display == current.display
    }).length == 0;
  }
}

var onlyInA = a.filter(comparer(b));
var onlyInB = b.filter(comparer(a));

result = onlyInA.concat(onlyInB);

console.log(result);