# \#113 One-liners

**URL:** <https://www.ruby-forum.com/t/113-one-liners/85416>\
**Category:** Ruby\
**Created:** [February 13, 2007, 10:00am UTC](https://www.ruby-forum.com/t/113-one-liners/85416 "2007-02-13T10:00:30Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![m4lloc](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/87869e/32.png) [@m4lloc](https://www.ruby-forum.com/u/m4lloc)\
**Post date:** [February 13, 2007, 10:00am UTC](https://www.ruby-forum.com/t/113-one-liners/85416/1 "2007-02-13T10:00:30Z")

</div>

Hi,

this is my solution. I found the first one-liner hard, and I’m not  
satisfied with my solution for it (it doesn’t work for negative numbers  
for example). But, I think the others are not bad.

####################

# Expected: “1,999,995.99”

quiz = 1999995.99  
a=quiz.to\_s.split’.’;r=a[0].reverse.gsub(/\d{3}\B/,  
‘\0,’).reverse+".#{a[1]}"  
puts r

####################

# Expected: [1, 2, [3]]

quiz = [1, [2, [3]]]  
r = []; quiz.each{|e| [\*e].each {|x| r \<\< x}}; r  
puts r.inspect

####################

# Expected: a shuffled array

quiz = [1, 2, 3, 4, 5]  
r = quiz.sort\_by{rand}  
puts r.inspect

####################

# Expected: the actual class object

module GhostWheel; module Expression; class LookAhead; end; end; end  
quiz = “GhostWheel::Expression::LookAhead”  
r = quiz.split(/::/).inject(Kernel){|t,k| t.const\_get(k)}  
puts r

####################

# Expected: “aaaaaaaaaaaaaaaaaaaa”

# “bbbbbbbbbbbbbbbbbbbb cccccccccccccccccc”

# “dddddddddddddddddddd”

quiz = “a” \* 20 + " " + “b” \* 20 + " " + “c” \* 18 + " " + “d” \* 20  
r = quiz.gsub(/(.{1,40}) /, “\1\n”)  
puts r

####################

# Expected: [“foo”, “oof”, “ofo”]

quiz = %w[foo bar baz oof foobar ofo]  
$; = //; f = quiz[0].split.sort; r = quiz.select{|e| e.split.sort == f}  
puts r  
$; = nil

####################

# Expected: “111100111011111110101”

# “110000111100101100101”

# “1100100111010111011011100010”

quiz = “You are dumb”  
r = quiz.gsub(/./) {|c| (c == ’ ') ? “\n” : ("%08b" % c[0])}  
puts r

####################

# Expected: a random line from the this File

File.open( **FILE** , “r”) do |quiz|  
a = quiz.read.split("\n"); r = a[rand(a.size)]  
end  
puts r

####################

# Expected: [15, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8,

4, 2, 1]  
quiz = 15  
r = [quiz]; while ((e = r.last) != 1) do r\<\<((e%2==0)?e/2:3\*e+1) end; r  
puts r.inspect

####################

# Expected: {“one” =\> {“two” =\> {“three” =\> {“four” =\> “five”}}}}

quiz = %w[one two three four five]  
r = quiz.reverse.inject{|h,v| {v=\>h}}  
puts r.inspect