Nil or enter with no input

Ruby
1

How can I tell if someone has enter nothing in a gets prompt, they only
press enter. I though maybe it was nil, but that doesn’t seem to work. I
though this was going to work nicely, but doesn’t.

Building and sorting an array.

array = []
word = ‘foo’

while word != nil
puts ‘Enter a word’
word = gets
array.push word
end

puts array.sort

2

Sorry I may have gotten it, check this out.

Building and sorting an array.

array = []
puts ‘Enter a word’
word = gets.chomp

while word != ‘’
array.push word
puts ‘Enter a word’
word = gets.chomp
end

puts array.sort

3

You might want to look into String#empty?

4

Am 29.03.2013 16:55, schrieb Phil H.:

How can I tell if someone has enter nothing in a gets prompt, they only
press enter. I though maybe it was nil, but that doesn’t seem to work. I
though this was going to work nicely, but doesn’t.

The string will be “\n” (a string that contains only a newline):

if gets == “\n”

or

if gets.chomp.empty?

will work.

5

Phil H. wrote:

puts ‘Enter a word’
word = gets
array.push word
end

puts array.sort

Using enter even with no other character will return a \r\n or \n
depending upon your operating system

Tom R.

6

On Fri, Mar 29, 2013 at 5:42 PM, Joel P. [email protected]
wrote:

You might want to look into String#empty?

That alone is not sufficient. You need to at least throw String#chomp
in
the mix:

array = []
word = nil

do
puts ‘Enter a word’
word = gets.chomp # cut off line endings
array.push word unless word.empty?
end until word.empty?

puts array.sort

Another approach would verify that the string does indeed contain a
word:

…
do
puts ‘Enter a word’
word = gets.chomp # cut off line endings
array.push word unless /\A\w+\z/ =~ word
end until word.empty?

We can also avoid the duplicate check:

array = []
word = nil

loop do
puts ‘Enter a word’
word = gets.chomp # cut off line endings
break if word.empty?
array.push word
end

puts array.sort

Kind regards

robert

7

Robert K. wrote in post #1103733:

You might want to look into String#empty?
That alone is not sufficient. You need to at least throw String#chomp
in the mix:

I he was already using chomp, so I didn’t see a point in mentioning it
:slight_smile:

8

On Sat, Mar 30, 2013 at 9:16 AM, Joel P. [email protected]
wrote:

Robert K. wrote in post #1103733:

You might want to look into String#empty?
That alone is not sufficient. You need to at least throw String#chomp
in the mix:

I he was already using chomp, so I didn’t see a point in mentioning it
:slight_smile:

Right you are. I am sorry, I didn’t notice Phil added it in his second
post.

Cheers

robert