How to convert lowercase string to uppercase and vice versa?

Question

I am trying to write a program which converts all uppercase characters in a string to lowercase and lowercase characters to uppercase.For example if the string is "abcdE", it will return after coversion "ABCDe". This is what I have tried so far

class String
    def is_upper?
        self == self.upcase
    end

    def is_lower?
        self == self.downcase
    end
end

s = gets.chomp

if s.length <= 100
    a = s.split(//)
    b, c = Array.new
    a.each do |m|
        if m.is_upper? 
            b.push(m.downcase)
        end
        if m.is_lower?
            b.push(m.upcase)
        end
    end
    c = b.join
end

However I can assess that this program is very erroneous. I am still a novice learner. So forgive me if my solution program is very wrong.Please help me to find a correct and easier solution.

Answer 1

No need to invent the wheel again.

There is already a method named swapcase in ruby to accomplish this.

For ex-

"Hello".swapcase          #=> "hELLO"
"cYbEr_PuNk11".swapcase   #=> "CyBeR_pUnK11"

You can find more details here-

http://ruby-doc.org/core-2.2.0/String.html#method-i-swapcase