How deeply does The Well-Grounded Rubyist, Fourth Edition cover puts?

Explains newline handling, contrasts print, demonstrates file handles, and notes the nil return value in irb.

Puts

As explained in The Well-Grounded Rubyist, Fourth Edition

puts is a Ruby output method that writes objects to an IO stream and normally appends a newline after each line.

puts is Ruby’s everyday output method. It writes a value to an output stream and normally appends a newline, making each printed line begin after the previous one. If the value already ends with a newline, puts does not add another. section 1.1.6

Use puts to produce readable line-oriented output:

puts can write calculated values as well as strings. section 1.1.6
Use print when adjacent output must remain on the same line; a trailing newline must then be supplied explicitly. section 1.1.6
Calling puts on an open file handle, such as fh.puts fahrenheit, writes the value to that file rather than the screen. section 1.1.7
In irb, puts displays its output and returns nil, so irb may show both the printed line and => nil. section 1.4.2

Printing a conversion result

celsius = gets.to_i fahrenheit = (celsius * 9 / 5) + 32 puts "The Fahrenheit equivalent is #{fahrenheit}." section 1.1.7

How The Well-Grounded Rubyist, Fourth Edition covers it

Cover of The Well-Grounded Rubyist, Fourth Edition

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Related concepts

printcontrasts with · Print is a programming operation that writes a value or its textual representation to an output destination, often standard output.
to_sused by · to_s is a Ruby conversion method that returns a string representation of its receiver.
IOused by · IO is an abstraction representing input/output or other side-effecting computations and operations, often as composable values whose execution is separately controlled.
standard outputuses · Standard output is a process's conventional stream for writing ordinary program output, which may be directed to a terminal, file, pipe, or other destination.
end-of-file indicatorproduces · An end-of-file indicator is a condition, signal, or convention indicating that no more input data is available from a file or stream.

This explainer was generated by Manning's knowledge graph from the text of The Well-Grounded Rubyist, Fourth Edition. The section links point to the parts of the book it draws on.