# diffKeys()
The diffKeys method compares the collection against another collection or a plain object based on its keys. This method will return the key / value pairs in the original collection that are not present in the given collection:
const collection = collect({
a: 'a',
b: 'b',
c: 'c',
d: 'd',
});
const diff = collection.diffKeys({
b: 'b',
d: 'd',
});
diff.all();
// { a: 'a', c: 'c' }