How to remove duplicate values from an array in PHP

Question

How can I remove duplicate values from an array in PHP

User · Accepted Answer

Use array unique     Example    array   array 1  2  2  3    array   array unique  array      Array is now  1  2  3

User · Answer

explode      implode      array unique explode       YOUR ARRAY       This will take care of key associations and serialize the keys for the resulting new array  -

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lt  php  a array  quot 1 quot   gt  quot 302 quot   quot 2 quot   gt  quot 302 quot   quot 3 quot   gt  quot 276 quot   quot 4 quot   gt  quot 301 quot   quot 5 quot   gt  quot 302 quot    print r array values array unique  a       gt    output - gt  Array    0    gt  302  1    gt  276  2    gt  301

User · Answer

I have done this without using any function    arr   array  1    2    3    4    5    4    2    1      len   count  arr   for   i   0   i  lt   len   i         temp    arr  i      j    i    for   k   0   k  lt   len   k          if   k     j          if   temp     arr  k             echo  temp   lt br gt             arr  k                            for   i   0   i  lt   len   i        echo  arr  i       lt br gt  lt br gt

User · Answer

If you concern in performance and have simple array  use   array keys array flip  array      It s many times faster than array unique

User · Answer

Remove duplicate values from an associative array in PHP    arrDup   Array   0    gt   aaa-aaa     SKU    gt   aaa-aaa     1    gt   12 1 1     date    gt   12 1 1     2    gt   1 15     cost    gt   1 15      foreach  arrDup as  k   gt    v     if    isset   hold  v            hold  v  1    else       unset  arrDup  k        Array    0     aaa-aaa  1     12 1 1  2     1 15

User · Answer

There can be multiple ways to do these  which are as follows    first method  filter   array map  unserialize   array unique array map  serialize    arr        second method  array   array unique  arr  SORT REGULAR

User · Answer

a   array 1  2  3  4     b   array 1  6  5  2  9     c   array merge  a   b    unique   array keys array flip  c    print r  unique

User · Answer

Remove duplicate values from an associative array in PHP    arrDup   Array   0    gt   aaa-aaa     SKU    gt   aaa-aaa     1    gt   12 1 1     date    gt   12 1 1     2    gt   1 15     cost    gt   1 15      foreach  arrDup as  k   gt    v     if    isset   hold  v            hold  v  1    else       unset  arrDup  k        Array    0     aaa-aaa  1     12 1 1  2     1 15

User · Answer

Depending on the size of your array  I have found   array   array values  array flip  array flip   array          can be faster than array unique

User · Answer

lt  php  arr1    1 1 2 3 4 5 6 3 1 3 5 3 20       print r arr unique  arr1      function arr unique  arr      sort  arr      curr    arr 0      uni arr      arr 0     for  i 0   i lt count  arr   i           if  curr     arr  i              uni arr      arr  i            curr    arr  i                 return  uni arr

User · Answer

sometimes array unique   is not the way  if you want get unique AND duplicated items      unique array     A1      A2      A1        duplicated array     foreach  unique as  k  gt  v     if    kt array search  v  unique     false and  k   kt      unset  unique  kt      duplicated    v        sort  unique      optional sort  duplicated      optional   results on  array   0   gt      1   gt   A1   2   gt   A2         unique     array   0   gt      1   gt      2   gt      3   gt   A1         duplicated

User · Answer

sometimes array unique   is not the way  if you want get unique AND duplicated items      unique array     A1      A2      A1        duplicated array     foreach  unique as  k  gt  v     if    kt array search  v  unique     false and  k   kt      unset  unique  kt      duplicated    v        sort  unique      optional sort  duplicated      optional   results on  array   0   gt      1   gt   A1   2   gt   A2         unique     array   0   gt      1   gt      2   gt      3   gt   A1         duplicated

User · Answer

function arrayUnique  myArray         newArray   Array        if  is array  myArray                 foreach  myArray as  key  gt  val                        if  is array  val                                  val2   arrayUnique  val                             else                                val2    val                   newArray array unique  myArray                    newArray deleteEmpty  newArray                   break                            if   empty  val2                                  newArray  key     val2                                    return   newArray      function deleteEmpty  myArray         retArray  Array        foreach  myArray as  key  gt  val                if    key lt  gt      amp  amp    val lt  gt                             retArray  key     val                      return  retArray

User · Answer

arrDuplicate   array        1 3    5    foreach array unique  arrDuplicate  as  v     if  v          arrRemoved    v      print r  arrRemoved

User · Answer

That s a great way to do it  Might want to make sure its output is back an array again  Now you re only showing the last unique value   Try this    arrDuplicate   array        1 3    5    foreach  array unique  arrDuplicate  as  v     if  v           arrRemoved      v      print r   arrRemoved

User · Answer

explode      implode      array unique explode       YOUR ARRAY       This will take care of key associations and serialize the keys for the resulting new array  -

User · Answer

arrDuplicate   array        1 3    5    foreach array unique  arrDuplicate  as  v     if  v          arrRemoved    v      print r  arrRemoved

User · Answer

An alternative for array unique   function    Using Brute force algorithm        1  This our array with duplicated items   matches     jorge   melvin   chelsy   melvin   jorge   smith        2  Container for the new array without any duplicated items   arr           3  get the length of the duplicated array and set it to the var len to be use for for loop   len   count  matches       4  If matches array key  i  current loop Iteration is not available in    4  the array  arr then push the current iteration key value of the matches  i     4  to the array arr   for  i 0  i  if array search  matches  i    arr      false        array push  arr  matches  i           print the array  arr  print r  arr      Result  Array    0    gt  jorge  1    gt  melvin  2    gt  chelsy  3    gt  smith

User · Answer

try this short  amp  sweet code -    array   array  1 4 2 1 7 4 9 7 5 9    unique   array     foreach  array as  v     isset  k  v        k  v  1   amp  amp   unique      v       var dump  unique     Output -   array 6       0   gt    int 1     1   gt    int 4     2   gt    int 2     3   gt    int 7     4   gt    int 9     5   gt    int 5

User · Answer

array   array  a    gt   moon    star    b    gt   moon    star    sky        Deleting the duplicate items  result   array unique  array   print r  result     ref   Demo

User · Answer

There can be multiple ways to do these  which are as follows    first method  filter   array map  unserialize   array unique array map  serialize    arr        second method  array   array unique  arr  SORT REGULAR

User · Answer

It can be done through function I made three function duplicate returns the values which are duplicate in array   Second function single return only those values which are single mean not repeated in array and third and full function return all values but not duplicated if any value is duplicated it convert it to single   function duplicate  arr         duplicate       count   array count values  arr       foreach  arr as  key   gt   value            if   count  value   gt  1                 duplicate  value     value                      return  duplicate    function single  arr         single       count   array count values  arr       foreach  arr as  key   gt   value            if   count  value     1                 single  value     value                      return  single    function full  arr   arry         full    arr    arry      sort  full       return  full

User · Answer

result   array    foreach   array as  key   gt   value     if  in array  value   result        result  key   value

User · Answer

That s a great way to do it  Might want to make sure its output is back an array again  Now you re only showing the last unique value   Try this    arrDuplicate   array        1 3    5    foreach  array unique  arrDuplicate  as  v     if  v           arrRemoved      v      print r   arrRemoved

User · Answer

Find duplicates    arr   array        unique         duplicate         distinct         justone         three3         duplicate         three3         three3         onlyone        unique   array unique  arr     dupes   array diff key   arr   unique            array  5  gt  duplicate   6  gt  three3  7  gt  three3        count duplicates  array count values  dupes      array   duplicate   gt 1   three3   gt 2

User · Answer

if    in array  classified- gt category  arr                                                 arr      classified- gt category                                     gt                lt  php   endwhile  wp reset query      gt    first time check value in array and found same value ignore it

User · Answer

lt  php  a array  quot 1 quot   gt  quot 302 quot   quot 2 quot   gt  quot 302 quot   quot 3 quot   gt  quot 276 quot   quot 4 quot   gt  quot 301 quot   quot 5 quot   gt  quot 302 quot    print r array values array unique  a       gt    output - gt  Array    0    gt  302  1    gt  276  2    gt  301

User · Answer

We can create such type of array to use this last value will be updated into column or key value and we will get unique value from the array         array   array  1 3 4 2 1 7 4 9 7 5 9        data array        foreach  array as  value              data  value    value              array keys  data       OR     array values  data

User · Answer

result   array    foreach   array as  key   gt   value     if  in array  value   result        result  key   value

User · Answer

If you concern in performance and have simple array  use   array keys array flip  array      It s many times faster than array unique

User · Answer

Here I ve created a second empty array and used for loop with the first array which is having duplicates  It will run as many time as the count of the first array  Then compared with the position of the array with the first array and matched that it has this item already or not by using in array  If not then it ll add that item to second array with array push    a   array 1 2 3 1 3 4 5    count   count  a    b       for  i 0   i lt  count   i         if  in array  a  i    b            array push  b   a  i            print r   b

User · Answer

Use array values array unique  array     array unique  for unique array array values  for reindexing

User · Answer

An alternative for array unique   function    Using Brute force algorithm        1  This our array with duplicated items   matches     jorge   melvin   chelsy   melvin   jorge   smith        2  Container for the new array without any duplicated items   arr           3  get the length of the duplicated array and set it to the var len to be use for for loop   len   count  matches       4  If matches array key  i  current loop Iteration is not available in    4  the array  arr then push the current iteration key value of the matches  i     4  to the array arr   for  i 0  i  if array search  matches  i    arr      false        array push  arr  matches  i           print the array  arr  print r  arr      Result  Array    0    gt  jorge  1    gt  melvin  2    gt  chelsy  3    gt  smith

User · Answer

I have done this without using any function    arr   array  1    2    3    4    5    4    2    1      len   count  arr   for   i   0   i  lt   len   i         temp    arr  i      j    i    for   k   0   k  lt   len   k          if   k     j          if   temp     arr  k             echo  temp   lt br gt             arr  k                            for   i   0   i  lt   len   i        echo  arr  i       lt br gt  lt br gt

User · Answer

Here I ve created a second empty array and used for loop with the first array which is having duplicates  It will run as many time as the count of the first array  Then compared with the position of the array with the first array and matched that it has this item already or not by using in array  If not then it ll add that item to second array with array push    a   array 1 2 3 1 3 4 5    count   count  a    b       for  i 0   i lt  count   i         if  in array  a  i    b            array push  b   a  i            print r   b

User · Answer

Depending on the size of your array  I have found   array   array values  array flip  array flip   array          can be faster than array unique

User · Answer

function arrayUnique  myArray         newArray   Array        if  is array  myArray                 foreach  myArray as  key  gt  val                        if  is array  val                                  val2   arrayUnique  val                             else                                val2    val                   newArray array unique  myArray                    newArray deleteEmpty  newArray                   break                            if   empty  val2                                  newArray  key     val2                                    return   newArray      function deleteEmpty  myArray         retArray  Array        foreach  myArray as  key  gt  val                if    key lt  gt      amp  amp    val lt  gt                             retArray  key     val                      return  retArray

User · Answer

a   array 1  2  3  4     b   array 1  6  5  2  9     c   array merge  a   b    unique   array keys array flip  c    print r  unique

User · Answer

The only thing which worked for me is    array   array unique  array  SORT REGULAR     Edit   SORT REGULAR keeps the same order of the original array

User · Answer

array   array  a    gt   moon    star    b    gt   moon    star    sky        Deleting the duplicate items  result   array unique  array   print r  result     ref   Demo

User · Answer

if    in array  classified- gt category  arr                                                 arr      classified- gt category                                     gt                lt  php   endwhile  wp reset query      gt    first time check value in array and found same value ignore it

User · Answer

The array unique function is just one of the really useful native functions from PHP for dealing with arrays  I recently wrote a piece on them and the spread operator to modifying and manipulating PHP arrays  https   wp-helpers com 2021 02 27 php-arrays-functions-and-spread-operator-in-wp-context

User · Answer

Use array values array unique  array     array unique  for unique array array values  for reindexing

User · Answer

The array unique function is just one of the really useful native functions from PHP for dealing with arrays  I recently wrote a piece on them and the spread operator to modifying and manipulating PHP arrays  https   wp-helpers com 2021 02 27 php-arrays-functions-and-spread-operator-in-wp-context

User · Answer

lt  php  arr1    1 1 2 3 4 5 6 3 1 3 5 3 20       print r arr unique  arr1      function arr unique  arr      sort  arr      curr    arr 0      uni arr      arr 0     for  i 0   i lt count  arr   i           if  curr     arr  i              uni arr      arr  i            curr    arr  i                 return  uni arr

User · Answer

Find duplicates    arr   array        unique         duplicate         distinct         justone         three3         duplicate         three3         three3         onlyone        unique   array unique  arr     dupes   array diff key   arr   unique            array  5  gt  duplicate   6  gt  three3  7  gt  three3        count duplicates  array count values  dupes      array   duplicate   gt 1   three3   gt 2

User · Answer

It can be done through function I made three function duplicate returns the values which are duplicate in array   Second function single return only those values which are single mean not repeated in array and third and full function return all values but not duplicated if any value is duplicated it convert it to single   function duplicate  arr         duplicate       count   array count values  arr       foreach  arr as  key   gt   value            if   count  value   gt  1                 duplicate  value     value                      return  duplicate    function single  arr         single       count   array count values  arr       foreach  arr as  key   gt   value            if   count  value     1                 single  value     value                      return  single    function full  arr   arry         full    arr    arry      sort  full       return  full

User · Answer

The only thing which worked for me is    array   array unique  array  SORT REGULAR     Edit   SORT REGULAR keeps the same order of the original array

User · Answer

We can create such type of array to use this last value will be updated into column or key value and we will get unique value from the array         array   array  1 3 4 2 1 7 4 9 7 5 9        data array        foreach  array as  value              data  value    value              array keys  data       OR     array values  data

User · Answer

try this short  amp  sweet code -    array   array  1 4 2 1 7 4 9 7 5 9    unique   array     foreach  array as  v     isset  k  v        k  v  1   amp  amp   unique      v       var dump  unique     Output -   array 6       0   gt    int 1     1   gt    int 4     2   gt    int 2     3   gt    int 7     4   gt    int 9     5   gt    int 5

[php] How to remove duplicate values from an array in PHP

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