Arrow functions are a more convinient and shorter way to write a function.
Arrow functions
are shorter to write, instead of function(){} write () => {}
var func = function(){};
assert.equal('' + func, '() => {}');instead {} use an expression, as return value
var func = () => {};
assert.equal(func(), 'I return too');one parameter can be written without parens
var func = p => param - 1;
assert.equal(func(25), 24);many params require parens
var func = param => param + param1;
assert.equal(func(23, 42), 23+42);the function body needs parens to return an object
var func = () => {iAm: 'an object'};
assert.deepEqual(func(), {iAm: 'an object'});