Angular - Compare two arrays with same number of objects but with different values and return the difference from second array

Question

I have 2 array of objects

arrayOne = [{objectType: 'License', objectId: 333, objectName: 'Test Object 1', dataType: 'String'}
        {objectType: 'Owner', objectId: 334, objectName: 'Test Object 2', dataType: 'String'},
        {objectType: 'Location', objectId: 335, objectName: 'Test Object 3', dataType: 'String'}]
        
arrayTwo = [{objectType: 'LICENSE', objectId: 333, objectName: 'Test Object 1', dataType: 'String'}
        {objectType: 'OWNER', objectId: 334, objectName: 'Test Object 4', dataType: 'Value List'},
        {objectType: 'LOCATION', objectId: 335, objectName: 'Test Object 3', dataType: 'String'}]

As we can see in arrayTwo , objectName and dataType is changed. It may be possible any of the property might change but the number of objects will be always same on both arrays.

So here, I need to pull the objects from arrayTwo which has been changed by comparing with arrayOne and store it in a new array say resultsArray ?

I checked the answers provided in How to get the difference between two arrays of objects in JavaScript it only talks about getting the differences based on one property, not any property. Please suggest on this. Thanks.

EDIT: Edited arrayTwo to have capital letters for objectType . I need to ignore the case and result should be case insensitive. Thanks

Answer 1

One option is to iterate through the first array elements, find the same element for the second array by its id and then check if any of its properties have changed:

 arrayOne = [{ objectType: 'License', objectId: 333, objectName: 'Test Object 1', dataType: 'String' }, { objectType: 'Owner', objectId: 334, objectName: 'Test Object 2', dataType: 'String' }, { objectType: 'Location', objectId: 335, objectName: 'Test Object 3', dataType: 'String' } ] arrayTwo = [{ objectType: 'License', objectId: 333, objectName: 'Test Object 1', dataType: 'String' }, { objectType: 'Owner', objectId: 334, objectName: 'Test Object 4', dataType: 'Value List' }, { objectType: 'Location', objectId: 335, objectName: 'Test Object 3', dataType: 'String' } ]; const changedObjects = arrayOne.filter(obj1 => { const obj2 = arrayTwo.find(x => x.objectId === obj1.objectId); return Object.keys(obj1).some(key => String(obj1[key]).toLowerCase().== String(obj2[key]);toLowerCase()); }). console;log(changedObjects);

EDIT: The above example will return the element from the arrayOne. In case you need the element with the new values you can reverse arrayOne and arrayTwo inside the function.