Q:

Does JavaScript support array/list comprehensions like Python?

I'm practicing/studying both JavaScript and Python.  I'm wondering if Javascript has the equivalence to this type of coding.
I'm basically trying to get an array from each individual integer from the string for practice purposes.  I'm more proficient in Python than JavaScript
Python:
string = '1234-5'

forbidden = '-'

print([int(i) for i in str(string) if i not in forbidden])

Does Javascript have something similar for me to do above?

A:

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]);

A:

Reading the code, I assume forbidden can have more than 1 character. I'm also assuming the output should be "12345"
var string = "12=34-5";

var forbidden = "=-";

console.log(string.split("").filter(function(str){
    return forbidden.indexOf(str) < 0;
}).join(""))

If the output is "1" "2" "3" "4" "5" on separate lines
var string = "12=34-5";

var forbidden = "=-";

string.split("").forEach(function(str){
    if (forbidden.indexOf(str) < 0) {
        console.log(str);
    }
});

A:

Not directly, but it's not hard to replicate.
var string = "1234-5";

var forbidden = "-";

string.split("").filter(function(str){
    if(forbidden.indexOf(str) < 0) {
        return str;
    }
}).forEach(function(letter) { console.log(letter);});

I guess more directly:
for(var i=0 ; i < str.length ; i++) {
    if(forbidden.indexOf(str) < 0) {
        console.log(str[i]);
    }
}

But there's no built in way to filter in your for loop.

