Ruby/Reflection/is a

x = 1                    # This is the value we"re working with
x.is_a? Fixnum           # true: x is a Fixnum
x.is_a? Integer          # true: x is an Integer
x.is_a? Numeric          # true: x is a Numeric
x.is_a? Comparable       # true: works with mixin modules, too
x.is_a? Object           # true for any value of x