Object#tap

obj.tap { |x| block } -> obj

Returns: Object · Updated March 13, 2026 · Core Classes

blocks debugging method-chaining

tap yields the receiver to a block and then returns the object itself. This simple method is incredibly useful for debugging and method chaining without creating intermediate variables.

Syntax

obj.tap { |x| block }

Parameters

Parameter	Type	Default	Description
`block`	`Block`	required	A block that receives the object as its parameter

Examples

Basic usage

# tap returns the object itself
message = "Hello, World!"
message.tap { |m| puts m }
# Hello, World!
# => "Hello, World!"

Debugging method chains

# tap shines when debugging pipelines
result = [1, 2, 3, 4, 5]
  .map { |x| x * 2 }
  .tap { |arr| puts "After map: #{arr.inspect}" }
  .select { |x| x > 4 }
  .tap { |arr| puts "After select: #{arr.inspect}" }

# After map: [2, 4, 6, 8, 10]
# After select: [6, 8, 10]
# => [6, 8, 10]

Setting up objects

# Configure an object in a single expression
config = {}.tap do |h|
  h[:host] = "localhost"
  h[:port] = 3000
  h[:env] = "development"
end
# => { host: "localhost", port: 3000, env: "development" }

Common Patterns

Debugging in pipelines

tap shines when you need to inspect values mid-chain without disrupting the flow:

# Inspect without breaking the chain
data = [1, 2, 3]
  .map { |x| x ** 2 }
  .tap { |arr| puts "Squared: #{arr}" }
  .sum
# Squared: [1, 4, 9]
# => 14

Initializing objects

class Connection
  attr_accessor :host, :port, :ssl
end

conn = Connection.new.tap do |c|
  c.host = "localhost"
  c.port = 3000
  c.ssl = true
end