JavaScript Taskbook Level 2.7

Задание 1

A certain line is given:

javascript'a bc def ghij'

Convert all substrings with less than or equal to three letters to uppercase. In our case, we should get the following:

javascript'A BC DEF ghij'

Задание 2

Given a symbol, find out whether this symbol is uppercase or lowercase.

Задание 3

Given a certain number, for example, this one:

javascript123789

Remove all odd digits from this number. In our case, we get the following result:

javascript28