add() appends a new element to the end of a Set object.
- adds every value, of any type, only once
- is chainable
- call without params adds undefined
- 0, -0 and +0 are equal
set.add()Appends a new element to the end of a Set object.
Donate to NGO Julenka. Support Ukranians in need. Julenka is an NGO which my brother founded in 2011 to support Ukranian families and kids in need.add() appends a new element to the end of a Set object.