[elcapitan]

I like that type of code, so yes, maybe it's a darling.

It's easy to make it more readable by aligning the code with the dots, so that it becomes a pipeline:

  @sentence = @sentence.split(' ')
                       .map!{|x| x = x[0..0].upcase << x[1..-1]}
                       .join(' ')

I definitely prefer that to half a screen page of crappy imperative code, where people over time will add lots of side effects etc.

Besides, the middle part is clearly a strawman because

  @sentence = @sentence.split(' ')
                       .map!(&:capitalize)
                       .join(' ')

but yeah. ;)

[djur]

`map!`, `<<`, and `0..0` are all unnecessary and distracting here. The availability of `capitalize` aside, `map`, `+`, and `0` would be better choices.

[ibmthrowaway271]

As pointed out below, they aren't equivalent.

Compare the output of both when run against "foo bar WIBBLE"