text
stringlengths
0
444
paragraphs.each do |paragraph|
html += "<p>#{paragraph}</p>"
end
# good and also fast
html = ''
html << '<h1>Page title</h1>'
paragraphs.each do |paragraph|
html << "<p>#{paragraph}</p>"
end
----
=== Don't Abuse `gsub` [[dont-abuse-gsub]]
Don't use `String#gsub` in scenarios in which you can use a faster and more specialized alternative.
[source,ruby]
----
url = 'http://example.com'
str = 'lisp-case-rules'
# bad
url.gsub('http://', 'https://')
str.gsub('-', '_')
# good
url.sub('http://', 'https://')
str.tr('-', '_')
----
=== `String#chars` [[string-chars]]
Prefer the use of `String#chars` over `String#split` with empty string or regexp literal argument.
NOTE: These cases have the same behavior since Ruby 2.0.
[source,ruby]
----
# bad
string.split(//)
string.split('')
# good
string.chars
----
=== `sprintf` [[sprintf]]
Prefer the use of `sprintf` and its alias `format` over the fairly cryptic `String#%` method.
[source,ruby]
----
# bad
'%d %d' % [20, 10]
# => '20 10'
# good
sprintf('%d %d', 20, 10)
# => '20 10'
# good
sprintf('%<first>d %<second>d', first: 20, second: 10)
# => '20 10'
format('%d %d', 20, 10)
# => '20 10'
# good
format('%<first>d %<second>d', first: 20, second: 10)
# => '20 10'
----
=== Named Format Tokens [[named-format-tokens]]
When using named format string tokens, favor `%<name>s` over `%{name}` because it encodes information about the type of the value.
[source,ruby]
----
# bad
format('Hello, %{name}', name: 'John')
# good
format('Hello, %<name>s', name: 'John')
----
=== Long Strings [[heredoc-long-strings]]
Break long strings into multiple lines but don't concatenate them with `+`.
If you want to add newlines, use heredoc. Otherwise use `\`:
[source,ruby]
----
# bad
"Lorem Ipsum is simply dummy text of the printing and typesetting industry. " +
"Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, " +
"when an unknown printer took a galley of type and scrambled it to make a type specimen book."
# good
<<~LOREM