Advantages of removing element from collection as set with one object

Question

I found next code in official java docs:

collection.removeAll(Collections.singleton(element));

I couldn't figure out advantages of this approach. Why not usual element removing?

collection.remove(element);

Thanks!

Answer 1

The former removes all occurrences of the element within collection, the latter removes only first occurrence.

Answer 2

Acc. to docs:

consider the following idiom to remove all instances of a specified element, e, from a Collection, c

collection.removeAll(Collections.singleton(element));

while collection.remove(element); removes a single instance of the specified element from this collection

So, to remove all instances, you've to use a loop construct with latter approach. while with first one it's just one line job.