These are Haskell's functions ported to javascript. Some are missing and some don't behave exactly the same. You can try them with a console (firebug or others). All functions can be curried!! All list(array) functions do work on regular strings: filter( isVowel, 'hey how are you' ) == 'eoaeou'; take( 5, 'abcdefghi' ) == 'abcde'; maximum( 'ajcdbe' ) == 'j'; The function length is called length' Mo