␡
- Slicing an Array
- Iterating over an Array
- Creating Enumerable Classes
- Sorting an Array
- Iterating over Nested Arrays
- Modifying All the Values in an Array
- Sorting Nested Arrays
- Building a Hash from a Config File
- Sorting a Hash by Key or Value
- Eliminating Duplicate Data from Arrays (Sets)
- Working with Nested Sets
This chapter is from the book
This chapter is from the book
This chapter is from the book
This chapter is from the book
Modifying All the Values in an Array
Array#collect, also known as Array#map, is used to modify the values of an Array and return a new array.
['This', 'is', 'a', 'test!'].collect do |word|
word.downcase.delete '^A-Za-z'
end
#=> ["this", "is", "a", "test"]
If you want to do this on a nested Array, you need something a little stronger:
class Array
def collect_recur(&block)
collect do |e|
if e.is_a? Array
e.collect_recur(&block)
else
block.call(e)
end
end
end
end
[[1,2,3],[4,5,6]].collect_recur { |elem| elem**2 }
#=> [[1, 4, 9], [16, 25, 36]]