PHP Taskbook Level 2.7
Given a string:
'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:
'A BC DEF ghij'
Given a symbol, find out whether this symbol is uppercase or lowercase.
Given a certain number, for example, this one:
123789
Remove all odd digits from this number. In our case, we get the following result:
28
