The array_unique function can be taken seriously. It has this function. Let's take a look at an example of how PHP uses array_unique to reprocess two-dimensional arrays.
Version 5.2.9 of PHP adds array_unique support for multidimensional arrays. In dealing with multidimensional arrays, sort_flags parameters need to be set.
Duplicate terms of one-dimensional arrays:
The array_unique function can be used, with the following examples:
The code is as follows
$aa = array("apple", "banana", "pear", "apple", "wail", "watermalon");
$bb = array_unique($aa);
print_r($bb);The results are as follows:
Array ( [0] => apple [1] => banana [2] => pear [4] => wail [5] => watermalon )
Two-dimensional array de-duplicate terms
The code is as follows
For example:
$result = array(
0=>array('a'=>1,'b'=>'Hello'),
1=>array('a'=>1,'b'=>'other'),
2=>array('a'=>1,'b'=>'other'),
);Processed into
$result = array(
0=>array('a'=>1,'b'=>'Hello'),
1=>array('a'=>1,'b'=>'other')
);Method of use
array_unique($result, SORT_REGULAR);
Duplicates of two-dimensional arrays:
For two-dimensional arrays, we discuss two cases: one is that the value of a key name can not be repeated, deleting duplicate items; the other is that the internal one-dimensional arrays can not be exactly the same, and deleting duplicate items. Here is an example to illustrate:
Delete duplicates because the value of a key name cannot be duplicated
The code is as follows
//Defined function
function assoc_unique($arr, $key) {
$tmp_arr = array();
foreach ($arr as $k => $v) {
if (in_array($v[$key], $tmp_arr)) {//Search for whether $v[$key] exists in the $tmp_arr array and return true if it exists
unset($arr[$k]);
} else {
$tmp_arr[] = $v[$key];
}
}
sort($arr); //Sort functions sort arrays
return $arr;
}
//Example
$aa = array(
array('id' => 1, 'name' => 'Zhang San'),
array('id' => 1, 'name' => 'Li Si'),
array('id' => 2, 'name' => 'Wang Wu'),
array('id' => 3, 'name' => 'Zhao Liu'),
array('id' => 4, 'name' => 'Zhao Liu')
);
$key = 'id'; //Specify key values
$news=assoc_unique($aa, $key);
echo '<pre>';
var_dump($news);
The results are as follows:
Array ( [0] => Array ( [id] => 1 [name] => Zhang San ) [1] => Array ( [id] => 2 [name] => Wang Wu ) [2] => Array ( [id] => 3 [name] => Zhao Liu ) [3] => Array ( [id] => 4 [name] => Zhao Liu ) )
2. Delete duplicates because the internal one-dimensional arrays are not identical.
The code is as follows
function array_unique_fb($array2D) {
foreach ($array2D as $v) {
$v = join(",", $v); //Dimension reduction, or implode, converts a one-dimensional array to a comma-connected string
$temp[] = $v;
}
$temp = array_unique($temp);//Remove duplicate strings, that is, duplicate one-dimensional arrays
foreach ($temp as $k => $v) {
$temp[$k] = explode(",", $v);//Reassemble the disassembled array
}
return $temp;
}
$aa = array(
array('id' => 123, 'name' => 'Zhang San'),
array('id' => 123, 'name' => 'Li Si'),
array('id' => 124, 'name' => 'Wang Wu'),
array('id' => 123, 'name' => 'Li Si'),
array('id' => 126, 'name' => 'Zhao Liu')
);
$bb = array_unique_fb($aa);
print_r($bb)Display results:
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 ) )