olemus
funktsiooniavaldiste lühema süntaksiga esitus JavaScriptis, kasutab tähist "==>"
= a compact alternative to a traditional JavasScript function expression

ülevaateid
https://codeburst.io/javascript-arrow-functions-for-beginners-926947fc0cdc
https://flaviocopes.com/javascript-arrow-functions/
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions
https://javascript.info/arrow-functions