Why are there so many slightly different ways to do the same thing in Ruby?

Question

I am learning Ruby. My background is C++/Java/C#. Overall, I like the language, but I am a little confused about why there are so many different ways to accomplish the same thing, each with their own slightly different semantics.

Take string creation, for example. I can use '', "", q%, Q%, or just % to create strings. Some forms support interpolation. Other forms allow me to specify the string delimiters.

Why are there five ways to create string literals? Why would I ever use non-interpolated strings? What advantage does the % syntax have over quoted literals?

I know there must be value in the redundency in Ruby, but my untrained eyes are not clearly seeing it. Please enlighten me.

Answer 1

Why would I ever use non-interpolated strings?

When you don't want the interpolation, of course. For example, perhaps you're outputting some documentation about string interpolation:

'Use #{x} to interpolate the value of x.'
=> "Use #{x} to interpolate the value of x."

What advantage does the % syntax have over quoted literals?

It lets you write strings more naturally, without the quotes, or when you don't want to escape a lot of things, analogous to C#'s string-literal prefix @.

%{The % syntax make strings look more "natural".}
=> "The % syntax makes strings look more \"natural\"."

%{<basket size="50">}
=> "<basket size=\"50\">"

There are many other %-notations:

%w{apple banana #{1}cucumber}   # [w]hitespace-separated array, no interpolation
=> ["apple", "banana", "\#{1}cucumber"]

%W{apple banana #{1}cucumber}   # [W]hitespace-separated array with interpolation
=> ["apple", "banana", "1cucumber"]

# [r]egular expression (finds all unary primes)
%r{^1?$|^(11+?)\1+$}
=> /^1?$|^(11+?)\1+$/

(1..30).to_a.select{ |i| ("1" * i) !~ %r{^1?$|^(11+?)\1+$} }
=> [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]

%x{ruby --version} # [s]hell command
=> "ruby 1.9.1p129 (2009-05-12 revision 23412) [x86_64-linux]\n"

There's also %s (for symbols) and some others.

Why are there five ways to create string literals?

This isn't terribly unusual. Consider C#, for example, which has several different ways to generate strings: new String(); ""; @""; StringBuilder.ToString(), et cetera.

Answer 2

I'm not a Ruby expert, but had you ever heard the term "syntactic sugar" ? Basically some programing languages offer different syntax to accomplish the same task. Some people could find one way easier than others due to his previous programing/syntax experience.