Title here
Summary here
Here we use range
to sum the numbers in a slice. Arrays work like this too.
nums = [2, 3, 4]
sum = 0
nums.each do |num|
sum += num
end
puts "sum: #{sum}"
range
on arrays and slices provides both the index and value for each entry. Above we didn’t need the index, so we ignored it. Sometimes we actually want the indexes though.
nums.each_with_index do |num, i|
if num == 3
puts "index: #{i}"
end
end
range
on map iterates over key/value pairs.
kvs = { "a" => "apple", "b" => "banana" }
kvs.each do |k, v|
puts "#{k} -> #{v}"
end
range
can also iterate over just the keys of a map.
kvs.each_key do |k|
puts "key: #{k}"
end
range
on strings iterates over Unicode code points. The first value is the starting byte index of the character and the second the character itself.
"go".each_char.with_index do |c, i|
puts "#{i} #{c.ord}"
end
Run the Ruby script:
$ ruby range_over_built_in_types.rb
sum: 9
index: 1
a -> apple
b -> banana
key: a
key: b
0 103
1 111