How to remove duplicates from a two-dimensional array in PHP

This article mainly introduces the method of removing duplicates from two-dimensional arrays in PHP. It analyzes the related operation skills of removing duplicates when PHP retains each key value in the form of examples. Friends who need it can refer to it. I hope it can help. Everyone.

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 completely Same, delete duplicate items:

The code is as follows:

<?php
$arr = array(
     &#39;0&#39;=>array(
          &#39;name&#39;=>&#39;james&#39;,
          &#39;age&#39;=>30,
          ),
     &#39;1&#39;=>array(
          &#39;name&#39;=>&#39;susu&#39;,
          &#39;age&#39;=>26,
          ),
      &#39;2&#39;=>array(
          &#39;name&#39;=>&#39;james&#39;,
          &#39;age&#39;=>30,
          ),
      &#39;new&#39;=>array(
          &#39;name&#39;=>&#39;kube&#39;,
          &#39;age&#39;=>37,
          ),
      &#39;list&#39;=>array(
          &#39;name&#39;=>&#39;kube&#39;,
          &#39;age&#39;=>27,
          ),
      );
printf("Before tranform the array:<br>");  //输出原来的数组
print_r($arr);
echo "<br/>";
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 $temp[]即为不保留原来键值
  }
  printf("After split the array:<br>");
  print_r($temp);  //输出拆分后的数组
  echo"<br/>";
  $temp =array_unique($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:<br>");
print_r($arr_new);
echo "<br/>";
?>

Output result:

Before tranform the array:  //原来数组
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: //拆分后数组
Array ( [0] => james,30 [1] => susu,26 [2] => james,30 [new] =>kube,37 [list] => kube,27 )
Duplicate removal of thearray: //去重后数组
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 be the same because a certain key value cannot be the same. Delete duplicate items:

Deduplication for 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,$key);
  printf("As for the givenkey->%s:<br>",$key);
  print_r($arr_key);
  echo "<br/>";
?>

Output results:

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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