PHP implements one-dimensional array and two-dimensional array deduplication function

This article mainly introduces PHP to implement the deduplication function of one-dimensional arrays and two-dimensional arrays, and analyzes related operating techniques such as traversing, judging, sorting, and deduplication of one-dimensional arrays and two-dimensional arrays in PHP based on examples. Friends in need can refer to the following

The example of this article describes the implementation of one-dimensional array and two-dimensional array deduplication function in PHP. Share it with everyone for your reference, the details are as follows:

Removal of duplicates in an array

Duplicates in one-dimensional arrays:

Usearray_unique function is enough, the usage example is as follows:

<?php
  $aa=array("1","2","3","3","2","watermalon");
  $bb=array_unique($aa);
  print_r($bb);
?>

The result is as follows:

Array ( [0] => 1 [1] => 2 [2] => 3 [5] => watermalon )

Repetition of two-dimensional array Item:

We will discuss two-dimensional arrays in two situations. One is because the value of a certain key name cannot be repeated and duplicates are deleted; the other is because the internal one-dimensional array cannot be completely The same, and delete duplicate items, the following example illustrates:

Because the value of a certain key name cannot be repeated, delete duplicate items

<?php
function assoc_unique($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]);
    }
    else {
     $tmp_arr[] = $v[$key];
    }
  }
  sort($arr); //sort函数对数组进行排序
  return $arr;
}
$aa = array(
  array(&#39;shopId&#39; => 1),
  array(&#39;shopId&#39; => 1),
  array(&#39;shopId&#39; => 2),
  array(&#39;shopId&#39; => 2)
);
$key = &#39;id&#39;;
$result = assoc_unique($aa, $key);
print_r($result);
?>

Display The result is:

Array ( [0] => Array ( [shopId] => 1 ) [1] => Array ( [shopId] => 2 ))

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