Get absolute value in Ruby
Get absolute value of target.
Use abs method of Numeric class for both of integer and float.
get_absolute_value.rb 
# Get absolute value of integer
print("Absolute value of  5 is ", 5.abs, "\n")
print("Absolute value of -5 is ", (-5).abs, "\n")

# Get absolute value of float
print("Absolute value of  5.5 is ", 5.5.abs, "\n")
print("Absolute value of -5.5 is ", (-5.5).abs, "\n")
Result 
$ ruby get_absolute_value.rb
Absolute value of  5 is 5
Absolute value of -5 is 5
Absolute value of  5.5 is 5.5
Absolute value of -5.5 is 5.5