JAVASCRIPT

array comprehension javascript

[for (i of [ 1, 2, 3 ]) i*i ]; 
// [ 1, 4, 9 ]

var abc = [ "A", "B", "C" ];
[for (letters of abc) letters.toLowerCase()];
// [ "a", "b", "c" ]

js array comprehension

//returns 0-9
[...Array(10).keys()]

//returns 1-10
[...Array(11).keys()].splice(1)

javascript list comprehension

use this tool to simplify lists:
https://codeamaze.com/web-viewer/javascript-viewer