How to determine and remove duplicate data in an array in PHP

if (count($array) != count(array_unique($array))) {
 echo 'The array has duplicate values';
}
?>

PHP remove duplicate array data

$input = array("a" => "green","", "red","b" => "green", "" ,"blue", "red","c" => "witer","hello","witer");
//$result = array_unique($input); //Remove duplicate elements
$result = a_array_unique ($input); //Leave only a single element
foreach($result as $aa)
{
echo $aa."";
}
function multi_unique($array) {
 foreach ( $array as $k=>$na)
 $new[$k] = serialize($na);
 $uniq = array_unique($new);
 foreach($uniq as $k=>$ser)
 $new1[$k] = unserialize($ser);
 return ($new1);
}
function a_array_unique($array)//Written better
{
 $out = array();
 foreach ($array as $key=>$value) {
 if (!in_array($value, $out))
{
 $out[$key] = $value;
 }
 }
 return $out;
}
?>

PHP array has a built-in function array_unique () to remove duplicate items, but PHP's array_unique function only applies to one-dimensional arrays. Not suitable for multi-dimensional arrays. The following implements the array_unique function of a two-dimensional array:

function unique_arr($array2D,$stkeep=false,$ndformat=true)
{
 // Determine whether to retain the first-level array key (the first-level array key can be non-numeric)
 if($stkeep) $stArr = array_keys($array2D);
 // Determine whether to retain the secondary array keys (all secondary array keys must be the same)
 if($ndformat) $ndArr = array_keys(end($array2D)) ;
 //Dimensionality reduction, you can also use implode to convert a one-dimensional array into a string connected with commas
 foreach ($array2D as $v){
 $v = join(",",$v);
 $ temp[] = $v;
 }
 //Remove repeated strings, that is, repeated one-dimensional arrays
 $temp = array_unique($temp);
 //Reassemble the disassembled array
 foreach ($ temp as $k => $v)
 {
 if($stkeep) $k = $stArr[$k];
 if($ndformat)
 {
 $tempArr = explode(",",$v);
 foreach($tempArr as $ndkey => $ndval) $output[$k][$ndArr[$ndkey]] = $ndval;
 }
 else $output[$k] = explode(",",$ v);
 }
 return $output;
}
?>

Test case:

$array2D = array('first'=>array('title'=>'1111','date'=>'2222'),'second'=> ;array('title'=>'1111','date'=>'2222'),'third'=>array('title'=>'2222','date'=>'3333 '));
print_r($array2D);
print_r(unique_arr($array2D,true));
?>

php determines whether the same value exists in the array array_unique 1 2 times One last page