How to remove duplicates from php array

藏色散人
Release: 2023-03-07 08:00:01
Original
3191 people have browsed it

How to remove duplicates from PHP arrays: 1. Use the array_unique function to remove duplicates from PHP one-dimensional arrays; 2. Use the customized "function assoc_unique($arr, $key){...}" method Remove duplicates from php two-dimensional array.

How to remove duplicates from php array

Recommended: "PHP Video Tutorial"

php array deduplication (one-dimensional array and two-dimensional array Dimensional array)

Removal of duplicate items in the array

Duplicate items in one-dimensional array:

Use The array_unique function is sufficient. The usage example is as follows:

   <?php
                   $aa=array("apple","banana","pear","apple","wail","watermalon");
                   $bb=array_unique($aa);
                   print_r($bb);
                ?>
Copy after login

The result is as follows:

Array ( [0] => apple [1] => banana [2] => pear [4] => wail [5] => watermalon ) 。
Copy after login

Duplicate items of two-dimensional array:

For two-dimensional array we The discussion is divided into 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. The following is an example:

一 Because the value of a certain button cannot be repeated, delete the repetitive item

       <?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;id&#39; => 123, &#39;name&#39; => &#39;张三&#39;),
            array(&#39;id&#39; => 123, &#39;name&#39; => &#39;李四&#39;),
            array(&#39;id&#39; => 124, &#39;name&#39; => &#39;王五&#39;),
            array(&#39;id&#39; => 125, &#39;name&#39; => &#39;赵六&#39;),
            array(&#39;id&#39; => 126, &#39;name&#39; => &#39;赵六&#39;)
            );
            $key = &#39;id&#39;;
            assoc_unique(&$aa, $key);
            print_r($aa);
            ?>
Copy after login

display result:

Array ( [0] => Array ( [id] => 123 [name] => 张三 ) [1] => Array ( [id] => 124 [name] => 王五 ) [2] => Array ( [id] => 125 [name] => 赵六 ) [3] => Array ( [id] => 126 [name] => 赵六 ) )
Copy after login

㈡ Because the internal one -dimensional array cannot be exactly the same, delete repeated items

#
      <?php
            function array_unique_fb($array2D){
                 foreach ($array2D as $v){
                     $v = join(",",$v); //降维,也可以用implode,将一维数组转换为用逗号连接的字符串
                     $temp[] = $v;
                 }
                 $temp = array_unique($temp);    //去掉重复的字符串,也就是重复的一维数组
                foreach ($temp as $k => $v){
                    $temp[$k] = explode(",",$v);   //再将拆开的数组重新组装
                }
                return $temp;
            }
            $aa = array(
            array(&#39;id&#39; => 123, &#39;name&#39; => &#39;张三&#39;),
            array(&#39;id&#39; => 123, &#39;name&#39; => &#39;李四&#39;),
            array(&#39;id&#39; => 124, &#39;name&#39; => &#39;王五&#39;),
            array(&#39;id&#39; => 123, &#39;name&#39; => &#39;李四&#39;),
            array(&#39;id&#39; => 126, &#39;name&#39; => &#39;赵六&#39;)
            );
            $bb=array_unique_fb($aa);
            print_r($bb)
            ?>
Copy after login

Display results:

Array ( [0] => Array ( [0] => 123 [1] => 张三 ) [1] => Array ( [0] => 123 [1] => 李四 ) [2] => Array ( [0] => 124 [1] => 王五 ) [4] => Array ( [0] => 126 [1] => 赵六 ) )
Copy after login

The above is the detailed content of How to remove duplicates from php array. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template