Dart set list collection operator
/*Dart also offers collection if and collection for, which you can use to build
collections using conditionals (if) and repetition (for).
Here’s an example of using collection if to create a list with three or four items
in it:*/
var nav = [
'Home',
'Furniture',
'Plants',
if (promoActive) 'Outlet'
];
/*Here’s an example of using collection for to manipulate the items of a list
before adding them to another list:*/
var listOfInts = [1, 2, 3];
var listOfStrings = [
'#0',
for (var i in listOfInts) '#$i'
];
assert(listOfStrings[1] == '#1');