Ruby substring downcase

Question

是否有更合適的方法來使一個子字符串比這個更簡單？：

string[a..b] = string[a..b].downcase

也許是這樣的：

string[a..b].downcase!

例如：

string = "RubyChangedMyMind"

string[1..string.length] = string[1..string.length].downcase 
# this is working but i want to know if there is more short way to do this
# (indeces may be different)
# something like string[a..b].downcase!

Answer 1

你可以做proc：

my_downcase = Proc.new { |str,n,m| str.chars.each_with_index.map{ |c,index| (n..m).include?(index) ? c.downcase : c }.join}

並隨時調用它：

my_downcase.call(string,range_from,range_to)

例如：

string = "dsadaDAdasdsadDADADadsadADD"
new_string = my_downcase.call(string,0,11)
#=> "dsadadadasdsadDADADadsadADD"