Array API: array.values()

Array.prototype.values returns an iterator for all values in the array

values() returns an iterator

const arr = ['k', 'e', 'y']; const iterator = arr.values(); assert.deepEqual(iterator.next(), {value: void 0, done: true});

use iterator.next() to drop first value

const arr = ['keys', 'values', 'entries']; const iterator = arr.values(); iterator.___(); assert.deepEqual([...iterator], ['values', 'entries']);

empty array contains no values

const arr = [...[...[...[...'1']]]]; const values = [...arr.values()]; assert.equal(values.length, 0);

a sparse array without real values has values though

const arr = [, 0]; const keys = [...arr.values()]; assert.deepEqual(keys, [void 0, void 0]);

also includes holes in sparse arrays

const arr = ['a',]; assert.deepEqual([...arr.values()], ['a', void 0, 'c']);

Required Knowledge

• `const` declaration (Block scope)
• array (Destructuring)
• protocol (Iterator)

Related Katas

Array API

• array.sort() basics
• array.sort() can take a compare function
• array.shift() (as introduced in ES3)
• array.push() (as introduced in ES3)
• Array.from()
• Array.of()
• array.fill()
• array.find()
• array.findIndex()
• array.entries()
• array.keys()
• array.values()
• array.includes()
• array.toReversed()

Difficulty Level

INTERMEDIATE

First Published

20 May 2015

Stats

5 tests to solve