instance method

JSON#dump

(::_ToJson obj, ?::Integer limit) -> ::String

(::_ToJson obj, ::JSON::_WritableIO anIO) -> ::JSON::_Write

(::_ToJson obj, ::JSON::_Write anIO, ?::Integer limit) -> ::JSON::_Write

JSON.dump(obj, io = nil, limit = nil)

ext/json/lib/json/common.rb View on GitHub ↗

# File tmp/rubies/ruby-4.0.0/ext/json/lib/json/common.rb, line 930
def dump(obj, anIO = nil, limit = nil, kwargs = nil)
  if kwargs.nil?
    if limit.nil?
      if anIO.is_a?(Hash)
        kwargs = anIO
        anIO = nil
      end
    elsif limit.is_a?(Hash)
      kwargs = limit
      limit = nil
    end
  end

  unless anIO.nil?
    if anIO.respond_to?(:to_io)
      anIO = anIO.to_io
    elsif limit.nil? && !anIO.respond_to?(:write)
      anIO, limit = nil, anIO
    end
  end

  opts = JSON._dump_default_options
  opts = opts.merge(:max_nesting => limit) if limit
  opts = opts.merge(kwargs) if kwargs

  begin
    State.generate(obj, opts, anIO)
  rescue JSON::NestingError
    raise ArgumentError, "exceed depth limit"
  end
end

Dumps obj as a JSON string, i.e. calls generate on the object and returns the result.

The default options can be changed via method JSON.dump_default_options.

Argument io, if given, should respond to method write; the JSON String is written to io, and io is returned. If io is not given, the JSON String is returned.
Argument limit, if given, is passed to JSON.generate as option max_nesting.

When argument io is not given, returns the JSON String generated from obj:

Example

obj = {foo: [0, 1], bar: {baz: 2, bat: 3}, bam: :bad}
json = JSON.dump(obj)
json # => "{\"foo\":[0,1],\"bar\":{\"baz\":2,\"bat\":3},\"bam\":\"bad\"}"

When argument io is given, writes the JSON String to io and returns io:

Example

path = 't.json'
File.open(path, 'w') do |file|
  JSON.dump(obj, file)
end # => #<File:t.json (closed)>
puts File.read(path)

Output:

Example

{"foo":[0,1],"bar":{"baz":2,"bat":3},"bam":"bad"}

See also .on_mixed_keys_hash #fast_generate .deprecated_singleton_attr_accessor #generate also in 4.1 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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