Set: set.add()

add() appends a new element to the end of a Set object.

adds every value, of any type, only once

const set = new Set(); const fn = () => {}; set.add(1); set.add(1); set.add(fn); set.add({fn}); assert.equal(set.size, 2);

is chainable

const set = new Set(); set.add.add; assert.equal(set.has(2), true);

call without params adds undefined

const set = new Set(); set.add assert.equal(set.has(void 0), true);

0, -0 and +0 are equal

const set = new Set(); set.add(); set.add(); assert.equal(set.has(+0), true);

Required Knowledge

• basics (Set)

Related Katas

Set

• basics
• set.add()
• set.delete()
• the API
• set.clear()

Difficulty Level

TBD

First Published

29 May 2015

Stats

4 tests to solve