struct

Symbol

A symbol is a constant that is identified by a name without you having to give it a numeric value.

:hello
:welcome
:"123"
:"symbol with spaces"

See Symbol literals in the language reference.

Internally a symbol is represented as an Int32, so it's very efficient.

You can't dynamically create symbols. When you compile your program, each symbol gets assigned a unique number.

Class methods

needs_quotes?(string) : Bool

Determines if a string needs to be quoted to be used for a symbol literal.

Symbol.needs_quotes? "string"      # => false
Symbol.needs_quotes? "long string" # => true

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Instance methods

!=(other : Symbol) : Bool

Returns true if self is not equal to other.

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<=>(other : Symbol)

Compares symbol with other based on String#<=> method. Returns -1, 0 or 1 depending on whether symbol is less than, equal to, or greater than other.

See String#<=> for more information.

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==(other : Symbol) : Bool

Returns true if self is equal to other.

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clone

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hash(hasher)

See Object#hash(hasher)

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inspect(io : IO) : Nil

Returns the symbol literal representation as a string.

:crystal.inspect # => ":crystal"

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to_i

Returns a unique number for this symbol.

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to_json(json : JSON::Builder) : Nil

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to_json_object_key

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to_s(io : IO) : Nil

Appends the symbol's name to the passed IO.

:crystal.to_s # => "crystal"

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to_s

Returns the symbol's name as a String.

:foo.to_s           # => "foo"
:"hello world".to_s # => "hello world"

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to_yaml(yaml : YAML::Nodes::Builder) : Nil

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