Kernel#puts

puts(*objects) -> nil

puts is a Kernel method that writes one or more objects to standard output (stdout), appending a newline character after each object. It’s the most common way to output text in Ruby scripts and is often used for debugging and displaying information to users.

Syntax

puts obj
puts obj1, obj2, obj3
puts *objects

Parameters

Parameter	Description
*objects	One or more objects to output. Each object is converted to a string using to_s and followed by a newline.

Examples

Basic Usage

puts "Hello, World!"
# Hello, World!

puts "Line 1"
puts "Line 2"
# Line 1
# Line 2

Multiple Objects

puts "Name:", "Alice", "Age:", 30
# Name:
# Alice
# Age:
# 30

Arrays

arr = ["apple", "banana", "cherry"]
puts arr
# apple
# banana
# cherry

nil and Booleans

puts nil    # (outputs empty line)
puts true   # true
puts false  # false

Common Patterns

Debugging

def calculate_total(prices)
  total = prices.sum
  puts "Debug: prices = #{prices.inspect}, total = #{total}"
  total
end

Formatted Output

name = "Bob"
age = 25
puts "Name: %s, Age: %d" % [name, age]
# Name: Bob, Age: 25

Writing to stderr

puts always writes to stdout. For stderr, use $stderr.puts:

$stderr.puts "Error: something went wrong"

Differences from Similar Methods

Method	Newline	Return Value	Special Behavior
puts	Yes	nil	Adds newline after each object
print	No	nil	No newline
p	Yes	The object(s)	Uses inspect instead of to_s
printf	No	nil	Formatted output (C-style)

print vs puts

print "Hello"
print "World"
# HelloWorld

puts "Hello"
puts "World"
# Hello
# World

p vs puts

puts "hello\n"    # hello (interprets escape)
p "hello\n"       # "hello\n" (shows raw string with newline literal)

See Also

• Kernel#print
• Kernel#printf
• Kernel#sprintf