Illustrated Ruby: Symbols

Symbols are a unique feature of Ruby. They may look like strings but are not!
Here’s a symbol. It starts with a colon.	`p :symbol`
Strings and symbols are not identical, even if their content look the same.	`p :symbol == "symbol"`
We can convert a symbol to a string, and back.	`p :symbol.to_s p 'string'.to_sym`
The contents of these two strings are equal, but they are not the same object.	`p "string".object_id == "string".object_id`
Contrary to strings, each symbol exists only once.	`p :symbol.object_id == :symbol.object_id`
To write more complex symbols, quotes can be used.	`p :'a single-quoted symbol'`
Quoting rules are the same as for strings, e.g interpolation is supported.	`p :"a double-quoted symbol #{2}"`
We can use `%s` to write symbols, as an equivalent to single-quoting. AS for strings, the delimiter can be changed. There’s no `%S` though.	`p %s(this symbol has spaces)`

$ ruby examples/symbols/symbols.rb
:symbol
false
"symbol"
:string
false
true
:"a single-quoted symbol"
:"a double-quoted symbol 2"
:"this symbol has spaces"

Next example: Arrays