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Ruby's percent notation can do more than strings

Percent Notation

We already know that that we can create strings using the percent notation:

%{<foo="bar's ton">} is perfectly fine Ruby.

Modifier

But there is more. The curly brackets ({}) are interchangable with most unicode characters (e.g. square brackets[]).
Furthermore, you can add a "modifier" to the percent notation to control the return type of the expression:

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%i Array of Symbols %q String %r Regular Expression %s Symbol %w Array of Strings %x Backtick (capture subshell result)*

Examples:

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%i[foo bar] => [:foo, :bar] %q[foo bar] => "foo bar"

Interpolation

To interpolate a dynamic value, swap the modifier with the corresponding uppercase letter:

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%I[a list of #{'inter'}polated symbols] => [:a, :list, :of, :interpolated, :symbols]

*Please keep in mind that we'd prefer Open3 for shell commands.

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Owner of this card:

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Michael Leimstädtner
Last edit:
7 months ago
by Emanuel De
Keywords:
%, percent, string, notation, literal, regular, expression, quotes, cucumber, step, definition, regex, short
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Posted by Michael Leimstädtner to makandra dev
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