https://repl.it/CZ17/119 created by sethopia

Short Stack (1.6 Extra Problems).js

/*
	SHORT STACK
	
	create a function shorten() that takes a number and an array of single-digit integers. shorten() should return the input number, with every digit from the array removed
	
	ex)
		shorten(1023, [1,2]) -->  03
		shorten(1245267194821, [2,3,4]) --> 15671981
*/

function shorten(num, arr) {
	return Number(num.toString().split('').filter(function(digit) {return arr.indexOf(parseInt(digit)) === -1;}).join(''));
}

console.log(shorten(1023, [1,2])); // 03
console.log(shorten(1245267194821, [2,3,4])); // 15671981

Short Stack (1.6 Extra Problems)_console_dump.txt

Native Browser JavaScript
>>> 3
15671981
=> NaN