A simple example of php array deduplication (one-dimensional and two-dimensional array deduplication)-PHP Tutorial-php.cn

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

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Release： 2016-07-25 08:55:38

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

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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);
? >

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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)
?>

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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 ) )