Iterate Array and (pretty)print

Ruby
1

Hi,

I am trying to iterate through an array, convert the output to a string
and puts that string.

CODE:

@hosts = [“test1”, “test2”, “test3”, “test4”
puts @hosts.each { |x| print x + “\n” }.to_s

CURRENT OUTPUT:

[“test1”, “test2”, “test3”, “test4”]

DESIRED OUTPUT:

However, I want this output to go into an email message, so I’m want to
lose the Square brackets and quotes, so it looks like this (and is a
string):

test1
test2
test3

Any ideas?

Thanks.

Dwight

2

[“test1”, “test2”, “test3”, “test4”]

Any ideas?

Hi there,

In this case I think a simple join would be appropriate:

irb(main):001:0> @hosts = [“test1”, “test2”, “test3”, “test4”]
=> [“test1”, “test2”, “test3”, “test4”]
irb(main):002:0> puts @hosts.join(“\n”)
test1
test2
test3
test4

Regards,
Chris W.
http://www.twitter.com/cwgem

3

hi,

u have output @hosts’ elements in the block? why would you add a puts in
front of it?

u can do it just with Array.join

puts hosts.join(“\n”)

On Tue, Sep 13, 2011 at 10:33 PM, dwight schrute [email protected]
wrote:

CURRENT OUTPUT:
test2

–
Best Regards,

Larry Lv
@ Baidu NLP

4

On Tue, Sep 13, 2011 at 4:40 PM, Larry Lv [email protected] wrote:

hi,

u have output @hosts’ elements in the block? why would you add a puts in
front of it?

u can do it just with Array.join

puts hosts.join(“\n”)

You don’t even need the join.

irb(main):001:0> @hosts = [“test1”, “test2”, “test3”, “test4”]
=> [“test1”, “test2”, “test3”, “test4”]
irb(main):002:0> puts @hosts
test1
test2
test3
test4
=> nil
irb(main):003:0>

Cheers

robert

5

irb(main):003:0>

Cheers

robert

But, he wants it to be a string.

print @hosts.map{|x| x + “\n”}.join

Harry

6

Thank you Harry! That is exactly what I needed :slight_smile:

Dwight

7

Except, I need to put the output into a string. When I use the to_s
method, I end up with square brackets and quotes:

irb(main):001:0> @hosts = [“test1”, “test2”, “test3”, “test4”]
=> [“test1”, “test2”, “test3”, “test4”]
irb(main):002:0> puts @hosts
test1
test2
test3
test4
=> nil
irb(main):003:0> puts @hosts.to_s
[“test1”, “test2”, “test3”, “test4”]
=> nil

8

On Tue, Sep 13, 2011 at 3:33 PM, dwight schrute [email protected]
wrote:

puts @hosts.each { |x| print x + “\n” }.to_s

Just for completeness since nobody has quite covered it yet,
@hosts.each { … } returns the receiver, which in this case is
@hosts, and then you call .to_s on the result. So, closer to the
argument actually passed to puts, you essentially have @hosts.to_s
which is “["test1", "test2", "test3", "test4"]”, which, when
puts’d, is [“test1”, “test2”, “test3”, “test4”]. However, in your
block you also print, so the real, full output should have been:

test1
test2
test3
test4
[“test1”, “test2”, “test3”, “test4”]

9

On Tue, Sep 13, 2011 at 4:51 PM, Robert K.
[email protected]wrote:

You don’t even need the join.

I think this is just an artefact of “puts” and not relevant for the
initial
problem.

If the original posters wants to have it in an e-mail, he will probably
will
want to interpolate in a template. Using simply the @hosts as is
suggested
above will then yield this:

$ ruby <<EOF
@hosts = [“test1”, “test2”, “test3”, “test4”]
puts “#{@hosts}”

EOF
test1test2test3test4

I think the OP probably needed to use ‘map’ instead of ‘each’.

pev@pev-desktop:~/a$ ruby <<EOF
@hosts = [“test1”, “test2”, “test3”, “test4”]
hosts_string = @hosts.join(“\n”)

puts hosts_string
EOF
test1
test2
test3
test4

HTH,

Peter