How to get the difference between two arrays of objects in JavaScript
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?
Solution 1:
Using only native JS, something like this will work:
const 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"}];
const 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"}];
// A comparer used to determine if two entries are equal.
const isSameUser = (a, b) => a.value == b.value && a.display == b.display;
// Get items that only occur in the left array,
// using the compareFunction to determine equality.
const onlyInLeft = (left, right, compareFunction) =>
left.filter(leftValue =>
!right.some(rightValue =>
compareFunction(leftValue, rightValue)));
const onlyInA = onlyInLeft(a, b, isSameUser);
const onlyInB = onlyInLeft(b, a, isSameUser);
const result = [...onlyInA, ...onlyInB];
console.log(result);
Solution 2:
For those who like one-liner solutions in ES6, something like this:
const arrayOne = [
{ 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" },
];
const arrayTwo = [
{ 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"},
];
const results = arrayOne.filter(({ value: id1 }) => !arrayTwo.some(({ value: id2 }) => id2 === id1));
console.log(results);
Solution 3:
You could use Array.prototype.filter()
in combination with Array.prototype.some()
.
Here is an example (assuming your arrays are stored in the variables result1
and result2
):
//Find values that are in result1 but not in result2
var uniqueResultOne = result1.filter(function(obj) {
return !result2.some(function(obj2) {
return obj.value == obj2.value;
});
});
//Find values that are in result2 but not in result1
var uniqueResultTwo = result2.filter(function(obj) {
return !result1.some(function(obj2) {
return obj.value == obj2.value;
});
});
//Combine the two arrays of unique entries
var result = uniqueResultOne.concat(uniqueResultTwo);