PHP array deduplication example and analysis_PHP tutorial

Duplicates of one-dimensional array:

Just use the array_unique function. The usage example is as follows:

Copy the code The code is as follows:

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

The results are as follows: Array ( [0] => apple [1] =>banana [2] => pear [4] => wail [5]=> watermalon ).

Duplicates of two-dimensional array:

We will discuss two-dimensional arrays in two situations. One is to delete duplicates because the value of a certain key name cannot be repeated; the other is to delete duplicates because the internal one-dimensional array cannot be exactly the same, as follows Example:

㈠Because the value of a certain key name cannot be repeated, delete duplicates

Copy code The code is as follows:                                                                                                                                                                                                                                                                                        out out of > unset($arr[$k]);

}
else {
$tmp_arr[] = $v[$key];
}
}
}
sort($arr ); //sort function sorts the array
           return $arr;
$ aa = Array >'李四'),
            array('id' => 124, 'name' =>''Wang Wu'),
            array('id' => 125, 'name' = >'Zhao Liu'),
        array('id' => 126, 'name' =>''Zhao Liu')
          ); assoc_unique(&$aa, $key);
                       print_r($aa); ] =>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) )


㈡Because the internal one-dimensional arrays cannot be exactly the same, duplicate items are deleted

Copy code

The code is as follows:

function array_unique_fb($array2D){
foreach ($array2D as $v){
$v = join( ",",$v); // For dimensionality reduction, you can also use implode to convert a one-dimensional array into a string connected with commas.
$temp[] = $v;
The duplicate string, that is, the duplicated one -dimensional array
FOREACH ($ TEMP As $ K = & GT; $ V) {
$ TEMP [$ k] = Explode (",", $ v); / /Reassemble the disassembled array
                                                                                                                                                                                                                                                                                             
$ aa = Array >'李四'),
            array('id' => 124, 'name' =>''Wang Wu'),
            array('id' => 123, 'name' = >'李四'),        array('id' => 126, 'name' =>'Zhao Liu')

                                                                                                                                   R> Print_r ($ BB)
? & Gt;


Show results: array ([0] = & gt; array ([0] = & gt; 123 [1] = & gt; Zhang San San ) [1] => Array ( [0]=> 123 [1] => Li Si) [2]=> Array ( [0] => 124 [1]=> Wang Wu) [ 4] => Array ( [0]=> 126 [1] => Zhao Liu))




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TechArticleDuplicate items of one-dimensional array: Use the array_unique function. The usage example is as follows: Copy the code as follows: ?php $aa=array("apple","banana","pear","apple","wail","watermalon"); $...