Create a function that will test if a string is a valid PIN or not via a regular expression.

A valid PIN has:

• Exactly 4 or 6 characters.
• Only numeric characters (0-9).
• No whitespace.

Examples

validate("121317") ➞ true

validate("1234") ➞ true

validate("45135") ➞ false

validate("89abc1") ➞ false

validate("900876") ➞ true

validate(" 4983") ➞ false

Notes

• Empty strings should return false when tested.
• If you need help, look into the Resources tab.