Creating a Ruby method that pads an Array
- by CJ Johnson
I'm working on creating a method that pads an array, and accepts 1. a desired value and 2. an optional string/integer value. Desired_size reflects the desired number of elements in the array. If a string/integer is passed in as the second value, this value is used to pad the array with extra elements. I understand there is a 'fill' method that can shortcut this - but that would be cheating for the homework I'm doing.
The issue: no matter what I do, only the original array is returned. I started here:
class Array
def pad(desired_size, value = nil)
desired_size >= self.length ? return self : (desired_size - self.length).times.do { |x| self << value }
end
end
test_array = [1, 2, 3]
test_array.pad(5)
From what I researched the issue seemed to be around trying to alter self's array, so I learned about .inject and gave that a whirl:
class Array
def pad(desired_size, value = nil)
if desired_size >= self.length
return self
else
(desired_size - self.length).times.inject { |array, x| array << value }
return array
end
end
end
test_array = [1, 2, 3]
test_array.pad(5)
The interwebs tell me the problem might be with any reference to self so I wiped that out altogether:
class Array
def pad(desired_size, value = nil)
array = []
self.each { |x| array << x }
if desired_size >= array.length
return array
else
(desired_size - array.length).times.inject { |array, x| array << value }
return array
end
end
end
test_array = [1, 2, 3]
test_array.pad(5)
I'm very new to classes and still trying to learn about them. Maybe I'm not even testing them the right way with my test_array? Otherwise, I think the issue is I get the method to recognize the desired_size value that's being passed in. I don't know where to go next. Any advice would be appreciated.
Thanks in advance for your time.
