CODEWITHSUNDEEP
ruby-on-railsrubystringsyntaxprinting
K. Berman
K. Berman

Reputation:

Using print instead of sprintf with %s and % and multiple string substitution arguments

In the following ruby code, the output becomes: "x y"

x = "x %s"
y = "y"
z = "z"
print x % y %z

The %z is ignored.

I want the output to be "x y z".

To understand the possibilities and limitations of the syntax of Ruby, I want to use only the print command and the %s and % flags. I know how to do this using sprintf but I want to know if there's a way to do it with just the 'print' command.

So I tried adding a second %s to the definition of the variable 'x':

x = "x %s %s"
y = "y"
z = "z"
print x % y %z

But I got this error:

in `%': too few arguments (ArgumentError)

With sprintf you could do this:

x = "x %s %s"
y = "y"
z = "z"
print (sprintf(x, y, z))

The output would be what I wanted:

x y z

But that's just too easy.

Is there a way to do this with just 'print' (not sprintf) and without using #{} or combining y and z into an array as [y,z]?

Upvotes: 1

Views: 2992

Answers (4)

jheriko
jheriko

Reputation: 3113

Use print "x #{y} #{z}".

I could not find much documentation easily with Google... however here are some pages where this usage is demonstrated:

http://www.rubycentral.com/pickaxe/tut_expressions.html

http://linuxgazette.net/issue81/ramankutty.html

http://metacpan.org/pod/Inline::Ruby

Upvotes: 2

K. Berman
K. Berman

Reputation:

The consensus seems to be that you can't avoid using the #{} substitution syntax. And the % notation only seems to work if you use an array [y,z] to combine the two variables into a single unit.

What I really wanted, though was some way to do this:

print x % y, z

without combining the y and z variables into one.

Perhaps this is not possible and you either have to:

  1. Use #{} substitution
  2. Combine y and z into an array and then call print x % [y,z]
  3. Use sprintf like this: print (sprintf(x, y, z))

and define x as:

x = "x %s %s"

Upvotes: 1

Brent.Longborough
Brent.Longborough

Reputation: 9775

Might this be what you want?:

irb(main):001:0> x = "x %s %s"
=> "x %s %s"
irb(main):002:0> y = "y"
=> "y"
irb(main):003:0> z = "z"
=> "z"
irb(main):004:0> print x % [y,z]
x y z=> nil

Upvotes: 0

krusty.ar
krusty.ar

Reputation: 4060

I don't actually understand what you want to do, but: 

irb(main):001:0> x = "x %s"
=> "x %s"
irb(main):002:0> y = "y %s"
=> "y %s"
irb(main):003:0> z = "z"
=> "z"
irb(main):004:0> print x % y % z
x y z=> nil

and: 

irb(main):006:0> x = "x %s %s"
=> "x %s %s"
irb(main):007:0> y = "y"
=> "y"
irb(main):008:0> z = "z"
=> "z"
irb(main):009:0> x % [y,z]
=> "x y z"

Upvotes: 3

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