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HomeBackend DevelopmentPHP TutorialPHP two-dimensional array deduplication method (retaining each key value while removing duplicate items) - uniqueness of two-dimensional array_PHP tutorial

How to deduplicate two-dimensional arrays in PHP (retaining each key value while removing duplicate items) -- the uniqueness of two-dimensional arrays

For the following two-dimensional array, it is required to deduplicate it:

$arr = array(
          '0'=>array(
                    'name'=>'james',
                    'age'=>30,
                    ),
          '1'=>array(
                    'name'=>'susu',
                    'age'=>26,
                    ),
          '2'=>array(
                    'name'=>'james',
                    'age'=>30,
                    ),
          'new'=>array(
                    'name'=>'kube',
                    'age'=>37,
                    ),
          'list'=>array(
                    'name'=>'kube',
                    'age'=>27,
                    ),
          );


1. The values ​​in the one-dimensional array inside the two-dimensional array cannot be exactly the same. Delete the duplicate items:

The code is as follows:

<!--?php
$arr = array(
          &#39;0&#39;=-->array(
                   &#39;name&#39;=>&#39;james&#39;,
                   &#39;age&#39;=>30,
                   ),
          &#39;1&#39;=>array(
                   &#39;name&#39;=>&#39;susu&#39;,
                   &#39;age&#39;=>26,
                   ),
           &#39;2&#39;=>array(
                   &#39;name&#39;=>&#39;james&#39;,
                   &#39;age&#39;=>30,
                   ),
           &#39;new&#39;=>array(
                   &#39;name&#39;=>&#39;kube&#39;,
                   &#39;age&#39;=>37,
                   ),
           &#39;list&#39;=>array(
                   &#39;name&#39;=>&#39;kube&#39;,
                   &#39;age&#39;=>27,
                   ),
           );
printf(Before tranform the array:
);   //输出原来的数组
print_r($arr);
echo 
;
function more_array_unique($arr=array()){
    foreach($arr[0] as $k => $v){
        $arr_inner_key[]= $k;   //先把二维数组中的内层数组的键值记录在在一维数组中
    }
    foreach ($arras $k => $v){
        $v =join(,,$v);    //降维 用implode()也行
        $temp[$k] =$v;      //保留原来的键值 $temp[]即为不保留原来键值
    }
    printf(After split the array:
);
    print_r($temp);    //输出拆分后的数组
    echo
;
    $temp =array_unique($temp);    //去重:去掉重复的字符串
    foreach ($tempas $k => $v){
        $a = explode(,,$v);   //拆分后的重组 如:Array( [0] => james [1] => 30 )
        $arr_after[$k]= array_combine($arr_inner_key,$a);  //将原来的键与值重新合并
    }
    //ksort($arr_after);//排序如需要:ksort对数组进行排序(保留原键值key) ,sort为不保留key值
    return$arr_after;
}
    $arr_new = more_array_unique($arr);  //调用去重函数
    printf(Duplicate removal of the array:
);
    print_r($arr_new);
echo 
;
?>


Output result:

Before transform the array: //original array
Array ( [0] => Array ( [name] => james [age] => 30 ) [1] => Array ([name] => susu [age] => 26 ) [2 ] => Array ( [name] => james [age]=> 30 ) [new] => Array ( [name] => kube [age] => 37 ) [list] => Array ( [name] => kube [age] => 27 ) )
After split the array: //Split the array
Array ( [0] => james,30 [1] => susu,26 [2] => james,30 [new] =>kube,37 [list] => kube,27 )
Duplicate removal of thearray: //Array after duplicate removal
Array ( [0] => Array ( [name] => james [age] => 30 ) [1] => Array ([name] => susu [age] => 26 ) [new ] => Array ( [name] => kube [age] => 37 ) [list] => Array ( [name] => kube [age] => 27 ) )

2. The one-dimensional array inside the two-dimensional array cannot have the same key value, so delete duplicates:

/*Deduplicate a certain key value*/

<!--?php
$arr= array(……);  //同上的二维数组
functionsecond_array_unique_bykey($arr, $key){
    $tmp_arr = array();
    foreach($arr as $k =--> $v)
    {
        if(in_array($v[$key], $tmp_arr))   //搜索$v[$key]是否在$tmp_arr数组中存在,若存在返回true
        {
            unset($arr[$k]); //销毁一个变量  如果$tmp_arr中已存在相同的值就删除该值
        }
        else {
            $tmp_arr[$k] = $v[$key];  //将不同的值放在该数组中保存
        }
   }
   //ksort($arr); //ksort函数对数组进行排序(保留原键值key)  sort为不保留key值
    return $arr;
   }
   $key =&#39;name&#39;;
   $arr_key = second_array_unique_bykey($arr,$key);
   printf(As for the givenkey->%s:
,$key);
   print_r($arr_key);
   echo 
;
?>


Output result:

As for the given key->name:
Array ( [0] => Array ( [name] => james [age] => 30 ) [1] => Array ( [name] => susu [age] => 26 ) [new ] => Array ( [name] => kube [age]=> 37 ) )

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