JavaScript Reference Map, Reduce, Filter

Map

Used for changing every item in an array (no-state)

See the Pen eJOzZB by Tyler Buchea (@tylerbuchea) on CodePen.

Reduce

Map method but with state [joinedWords]

See the Pen rxBLdz by Tyler Buchea (@tylerbuchea) on CodePen.

Filter

Returns an expression true or false for including or discluding array item

See the Pen EPYZKX by Tyler Buchea (@tylerbuchea) on CodePen.

Chaining

All three methods can be infinitely chained together & nested

See the Pen dGbNLa by Tyler Buchea (@tylerbuchea) on CodePen.

Resources

• http://cryto.net/~joepie91/blog/2015/05/04/functional-programming-in-javascript-map-filter-reduce/

• http://stackoverflow.com/questions/6120931/how-to-count-the-number-of-certain-element-in-an-array