33-not-very-secure.js

/* In this example you have to validate if a user input string is alphanumeric.
The given string is not nil, so you don't have to check that.
The string has the following conditions to be alphanumeric:
At least one character ("" is not valid)
Allowed characters are uppercase / lowercase latin letters and digits from 0 to 9
No whitespaces/underscore */

const alphanumeric = string => string.length > 0 &&
string.split('').filter(a => !a.match(/^[a-z0-9]+$/i)).length === 0;