Remove duplicate elements from array in Ruby

Question

I have a Ruby array which contains duplicate elements   array    1 2 2 1 4 4 5 6 7 8 5 6    How can I remove all the duplicate elements from this array while retaining all unique elements without using for-loops and iteration

User · Answer

Just another alternative if anyone cares.

You can also use the to_set method of an array which converts the Array into a Set and by definition, set elements are unique.

[1,2,3,4,5,5,5,6].to_set => [1,2,3,4,5,6]

User · Answer

If someone was looking for a way to remove all instances of repeated values  see  How can I efficiently extract repeated elements in a Ruby array     a    1  2  2  3  counts   Hash new 0  a each    v  counts v     1   p counts select    v  count  count    1   keys    1  3

User · Answer

Try using the XOR operator  without using built-in functions   a    3 2 3 2 3 5 6 7  sort   result   a reject with index do  ele index    res    a index 1    ele    res    0 end  print result   With built-in functions   a    3 2 3 2 3 5 6 7   a uniq

User · Answer

The simplest ways for me are these ones  array    1  2  2  3   Array to set array to set to a     1  2  3   Array uniq array uniq     1  2  3

User · Answer

You can  return the intersection   a    1 1 2 3  a  amp  a   This will also delete duplicates

User · Answer

You can remove the duplicate elements with the uniq method   array uniq      gt   1  2  4  5  6  7  8    What might also be useful to know is that uniq takes a block  so if you have a have an array of keys     bucket1 file1    bucket2 file1    bucket3 file2    bucket4 file2     and you want to know what the unique files are  you can find it out with   a uniq    f  f   d       map    p  p split      last

User · Answer

Just to provide some insight   require  fruity  require  set   array    1 2 2 1 4 4 5 6 7 8 5 6    1 000  def mithun sasidharan ary    ary uniq end  def jaredsmith ary    ary  amp  ary end  def lri ary    counts   Hash new 0    ary each    v  counts v     1     counts select    v  count  count    1   keys  end  def finks ary    ary to set end  def santosh mohanty ary      result   ary reject with index do  ele index        res    ary index 1    ele        res    0     end end  SHORT ARRAY    1 1 2 2 3 1  mithun sasidharan SHORT ARRAY      gt   1  2  3  jaredsmith SHORT ARRAY      gt   1  2  3  lri SHORT ARRAY      gt   3  finks SHORT ARRAY      gt    lt Set   1  2  3  gt  santosh mohanty SHORT ARRAY      gt   1  2  3  1   puts  Ruby v s    RUBY VERSION  compare do    mithun sasidharan   mithun sasidharan array       jaredsmith   jaredsmith array       lri   lri array       finks   finks array       santosh mohanty   santosh mohanty array    end   Which  when run  results in      gt  gt  Ruby v2 7 1    gt  gt  Running each test 16 times  Test will take about 2 seconds     gt  gt   mithun sasidharan is faster than  jaredsmith by 2x    0 1    gt  gt   jaredsmith is faster than  santosh mohanty by 4x    0 1  results differ   1  2  4  5  6  7  8  vs  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1         gt  gt   santosh mohanty is similar to  lri  results differ   1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6  7  8  5  6  1  2  1  4  5  6         gt  gt   lri is similar to  finks  results differ     vs   lt Set   1  2  4  5  6  7  8  gt     Note  these returned bad results    lri SHORT ARRAY      gt   3  finks SHORT ARRAY      gt    lt Set   1  2  3  gt  santosh mohanty SHORT ARRAY      gt   1  2  3  1

User · Answer

array   array uniq   uniq removes all duplicate elements and retains all unique elements in the array   This is one of many beauties of the Ruby language

[ruby-on-rails] Remove duplicate elements from array in Ruby

Examples related to ruby-on-rails

Examples related to arrays

Examples related to ruby

Examples related to duplicates