Difference between puts and print

ruby-talk
1

You can also say

p “hello”

…which is what I do when I’m in a hurry.

2

You can also say

p “hello”

…which is what I do when I’m in a hurry.

This differs from #puts calls #to_s on its arguments while #p calls #inspect.

Gavin

···

From: “Stephen Neu” sneu@iblp.org

3

And print is also an ‘inspect’ type call? (ie interrogates the string to see
if there are escaped characters?)

–Andrew

···

On Tue, Nov 26, 2002 at 01:36:26PM +0900, Gavin Sinclair wrote:

From: “Stephen Neu” sneu@iblp.org

You can also say
p “hello”

This differs from #puts calls #to_s on its arguments while #p calls #inspect.

4

From: “Stephen Neu” sneu@iblp.org

You can also say
p “hello”

This differs from #puts calls #to_s on its arguments while #p calls
#inspect.

And print is also an ‘inspect’ type call? (ie interrogates the string to see
if there are escaped characters?)

According to ‘ri’, #print calls #to_s on non-String arguments.

Gavin

···

From: “andrew delboy” andrew@cyber.com.au

On Tue, Nov 26, 2002 at 01:36:26PM +0900, Gavin Sinclair wrote:

5

Ok, let me see if I have gotten my head around this.

After a bit of mailing list searching, this is what I have
come up with.

Method Names | How they work

···

#print | using the #to_s on each item within
> the presented ‘string’, and appends a
> ‘space’ character after the concatonated
> strings (and the space can get redirected
> to another character) - irb seemed to not
> put spaces, but I havent tested it with
> the actual ruby interpreter…

#puts | using the #to_s on each item within
> the presented ‘string’, and appents a new
> line character after the concatonated
> strings (perhaps the newline character
> can be redirected to another character
> as well??)

#p | using the #inspect on each item within
> the presented ‘string’

#to_s | calls the ‘stringify method’ which prints
> a pretty version of the string (such as
> a way to print arrays in a meaningful way
> to a human)

#inspect | calls a debugging type of stringification:
> meaning that it will signify what type it
> is by placing square brackets around an
> array, curly braces around a hash and quotes
> around a string, etc…

Does this about sum up the differences??

–Andrew

6

Method Names | How they work

#print | using the #to_s on each item within
> the presented ‘string’, and appends a
> ‘space’ character after the concatonated
> strings (and the space can get redirected
> to another character) - irb seemed to not
> put spaces, but I havent tested it with
> the actual ruby interpreter…

I did test it with the interpreter. print does not put spaces by
default. This is the behaviour I would expect.

#puts | using the #to_s on each item within
> the presented ‘string’, and appents a new
> line character after the concatonated
> strings (perhaps the newline character
> can be redirected to another character
> as well??)

It joins the strings via newlines.

$ ruby -e ‘puts “hello”, “world”’
hello
world

#to_s | calls the ‘stringify method’ which prints
> a pretty version of the string (such as
> a way to print arrays in a meaningful way
> to a human)

This one is cool.

class Foo
def initialize
@var = “bar”
end
def to_s
“This is a customized string”
end
end

var = Foo.new

puts var

Prints out:
“This is a customized string”

7

I only expect the “space-adding” behavior in Python. Most other languages
that I’ve used won’t insert spaces where you don’t ask for them with a
“print”. Then again, I haven’t used that many languages, so maybe I don’t
know what the expected behavior should be :slight_smile:

-Brian W

Brian Wisti
brian@coolnamehere.com
http://coolnamehere.com/

···

At 02:54 PM 11/26/2002 +0900, you wrote:

Method Names | How they work

#print | using the #to_s on each item within
> the presented ‘string’, and appends a
> ‘space’ character after the concatonated
> strings (and the space can get redirected
> to another character) - irb seemed to not
> put spaces, but I havent tested it with
> the actual ruby interpreter…

I did test it with the interpreter. print does not put spaces by
default. This is the behaviour I would expect.

8

Whereas if you try the following:

···

p var

it prints:
#<Foo:0x401f36b4 @var=“bar”>

Is there a way to override this behavior? So you could put
something different much like the array or hash printout with
the #p method?

–Andrew

#to_s | calls the ‘stringify method’ which prints
> a pretty version of the string (such as
> a way to print arrays in a meaningful way
> to a human)

This one is cool.

class Foo
def initialize
@var = “bar”
end
def to_s
“This is a customized string”
end
end

var = Foo.new

puts var

Prints out:
“This is a customized string”

9

Whereas if you try the following:

p var

it prints:
#<Foo:0x401f36b4 @var=“bar”>

Is there a way to override this behavior? So you could put
something different much like the array or hash printout with
the #p method?

class Foo
def inspect
“Just override ‘inspect’”
end
end

p var # → “Just override ‘inspect’”

Notice that I didn’t have to do a ‘var Foo.new’ again. var was already a
Foo, so when I modified Foo, var was changed correspondigly.

···

–Andrew

#to_s | calls the ‘stringify method’ which prints
> a pretty version of the string (such as
> a way to print arrays in a meaningful way
> to a human)

This one is cool.

class Foo
def initialize
@var = “bar”
end
def to_s
“This is a customized string”
end
end

var = Foo.new

puts var

Prints out:
“This is a customized string”

10

Even better:

class Foo
def inspect
self.to_s
end
end

~Daniel

···

Whereas if you try the following:

p var

it prints:
#<Foo:0x401f36b4 @var=“bar”>

Is there a way to override this behavior? So you could put
something different much like the array or hash printout with
the #p method?

–Andrew

#to_s | calls the ‘stringify method’ which prints
> a pretty version of the string (such as
> a way to print arrays in a meaningful way
> to a human)

This one is cool.

class Foo
def initialize
@var = “bar”
end
def to_s
“This is a customized string”
end
end

var = Foo.new

puts var

Prints out:
“This is a customized string”