Get difference between 2 JavaScript Arrays

Question

Get difference between 2 JavaScript Arrays.

    var tagsStr = 'Tag 1,Tag 2,Tag 3';
    var oldTaskSelectedTagsArray = tagsStr.split(',');
    console.log(oldTaskSelectedTagsArray); // ['Tag 1', 'Tag 2', 'Tag 3']

    var newTagsStr = 'Tag 1,Tag 2,Tag 3,Tag 4';
    var newTaskSelectedTagsArray = newTagsStr.split(',');
    console.log(newTaskSelectedTagsArray); // ['Tag 1', 'Tag 2', 'Tag 3', 'Tag 4']

Using oldTaskSelectedTagsArray and newTaskSelectedTagsArray how can I get the difference of these 2 arrays? In this case would be Tag 4