php check array value for duplicate

Question

i have this below array:

PHP

$arr=array('A','A','B','C');

i want to check value and if values are duplicate must be alert error

PHP

$chk=array_count_values($array);
if ( $chk[0] < 1 || $chk[2] < 1 || $chk[3] < 1  || $chk[4] < 1 )
    echo 'array must be uniq';

Check the first "Related" link to the right: http://stackoverflow.com/questions/1170807/how-to-detect-duplicate-values-in-php-array?rq=1 .. If one of the values (see the accepted answer) > 0.. you have a duplicate.. — Damien Overeem, Mar 05 '13 at 08:34

Jacob Relkin · Accepted Answer · 2013-03-05T09:05:29.547

12

Using array_unique(), this can be easily refactored into a new function:

function array_is_unique($array) {
   return array_unique($array) == $array;
}

Example:

$array = array("a", "a", "b", "c");
echo array_is_unique($array) ? "unique" : "non-unique"; //"non-unique"

edited Mar 05 '13 at 09:05

answered Mar 05 '13 at 08:34

Jacob Relkin

+1 for short and sweet :-) – michi Mar 05 '13 at 08:36
For PHP >= 5.1, may I suggest array type hint: function array_is_unique(array $array) { ... } – StartupGuy Jun 18 '14 at 15:30

score 1 · Answer 2 · answered Mar 05 '13 at 08:34

1

Try this :

$arr  =   array('A','A','B','C');
if(count($arr) != count(array_unique($arr))){
  echo "array must be uniq";
}

answered Mar 05 '13 at 08:34

Prasanth Bendra

score 0 · Answer 3 · answered Mar 05 '13 at 08:34

0

Just try with:

if ( count($arr) != count(array_unique($arr)) ) {
  echo 'array must be uniq';
}

answered Mar 05 '13 at 08:34

hsz

score 0 · Answer 4 · answered Mar 05 '13 at 08:35

0

You could walk thhrough it with a foreach loop and then use the strpos function to see if a string contains duplicates

answered Mar 05 '13 at 08:35

Thijmen Venus

score 0 · Answer 5 · edited Jun 20 '20 at 09:12

0

array array_unique ( array $array [, int $sort_flags = SORT_STRING ] )

Takes an input array and returns a new array without duplicate values.

edited Jun 20 '20 at 09:12

Community

answered Mar 05 '13 at 08:36

Bigood

5 Answers5