Does JavaScript support array/list comprehensions like Python?
Given the question's Python code
print([int(i) for i in str(string) if i not in forbidden])
this is the most direct translation to JavaScript (ES2015):
const string = '1234-5';
const forbidden = '-';
console.log([...string].filter(c => !forbidden.includes(c)).map(c => parseInt(c)));
// result: [ 1, 2, 3, 4, 5 ]
Here is a comparison of the Python and JavaScript code elements being used: (Python -> Javascript):
- print -> console.log
- iterate over characters in a string -> spread operator
- list comprehension 'if' ->
Array.filter
- list comprehension 'for' ->
Array.map
- substr in str? -> string.includes
Update: Array comprehensions were removed from the standard. Quoting MDN:
The array comprehensions syntax is non-standard and removed starting with Firefox 58. For future-facing usages, consider using Array.prototype.map, Array.prototype.filter, arrow functions, and spread syntax.
See this answer for an example with Array.prototype.map
:
let emails = people.map(({ email }) => email);
Original answer:
Yes, JavaScript will support array comprehensions in the upcoming EcmaScript version 7.
Here's an example.
var str = "1234-5";
var ignore = "-";
console.log([for (i of str) if (!ignore.includes(i)) i]);