A simple example of php array deduplication (one-dimensional and two-dimensional array deduplication)

 $aa=array("apple","banana","pear","apple","wail","watermalon");
 $bb=array_unique($aa);
 print_r($bb);
?>

Output result: Array ( [0] => apple [1] => banana [2] => pear [4] => wail [5] => watermalon ) .

Second, duplicates of PHP two-dimensional array: For two-dimensional arrays, we will discuss two situations. One is because the value of a certain key name cannot be repeated and duplicates are deleted; The other is to remove duplicates because the internal one-dimensional arrays cannot be exactly the same.

Example 1, because the value of a certain key name cannot be repeated, delete the duplicates. Code:

 function assoc_unique($arr, $key)
 {
 $tmp_arr = array();
 foreach($arr as $k => $v)
 {
 if(in_array ($v[$key], $tmp_arr))//Search whether $v[$key] exists in the $tmp_arr array. If it exists, return true
 { // bbs.it-home.org
 unset($arr[ $k]);
 }
 else {
 $tmp_arr[] = $v[$key];
 }
 }
 sort($arr); //sort function sorts the array
 return $arr;
 }
 $aa = array(
 array('id' => 123, 'name' => 'Zhang San'),
 array('id' => 123, 'name' => '李思') ,
 array('id' => 124, 'name' => '王五'),
 array('id' => 125, 'name' => 'Zhao Liu'),
 array( 'id' => 126, 'name' => 'Zhao Liu')
 );
 $key = 'id';
 assoc_unique(&$aa, $key);
 print_r($aa);
 ? >

Output result: Array ( [0] => Array ( [id] => 123 [name] => Zhang San) [1] => Array ( [id] => 124 [name] => Wang Wu) [2] => Array ( [id] => 125 [name] => Zhao Liu) [3] => Array ( [id] => 126 [name] => Zhao Liu ) ) Example 2: Delete duplicates because the internal one-dimensional arrays cannot be exactly the same. Code:

 function array_unique_fb($array2D){
 foreach ($array2D as $v){
 $v = join(",",$v); //Dimension reduction can also be used implode, convert a one-dimensional array into a string connected by commas
 $temp[] = $v;
 } // bbs.it-home.org
 $temp = array_unique($temp); //Remove repeated characters String, that is, a repeated one-dimensional array
 foreach ($temp as $k => $v){
 $temp[$k] = explode(",",$v); //Then split the array Reassemble
 }
 return $temp;
 }
 $aa = array(
 array('id' => 123, 'name' => 'Zhang San'),
 array('id' => 123 , 'name' => '李思'),
 array('id' => 124, 'name' => '王五'),
 array('id' => 123, 'name' => '李思'),
 array('id' => 126, 'name' => 'Zhao Liu')
 );
 $bb=array_unique_fb($aa);
 print_r($bb)
 ?>

Output result:

Array ( [0] => Array ( [0] => 123 [1] => Zhang San) [1] => Array ( [0] => 123 [1] => Li Si) [2] => Array ( [0] => 124 [1] => Wang Wu) [4] => Array ( [0] => 126 [1] => Zhao Liu ) )