• php 数组排重


    一维数组的重复项

           使用array_unique函数即可,使用实例如下:

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

           结果如下:Array ( [0] => apple [1] => banana [2] => pear [4] => wail [5] => watermalon ) 。

    二维数组的重复项

          对于二维数组咱们分两种情况讨论,一种是因为某一键名的值不能重复,删除重复项;另一种因为内部的一维数组不能完全相同,而删除重复项,下面举例说明:

                ㈠因为某一键名的值不能重复,删除重复项

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

          显示结果为: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 ) )

            ㈡因内部的一维数组不能完全相同,而删除重复项

                <?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('id' => 123, 'name' => '张三'),
                array('id' => 123, 'name' => '李四'),
                array('id' => 124, 'name' => '王五'),
                array('id' => 123, 'name' => '李四'),
                array('id' => 126, 'name' => '赵六')
                );
                $bb=array_unique_fb($aa);
                print_r($bb)
                ?>

              显示结果: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 ) )  

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  • 原文地址:https://www.cnblogs.com/fyy-888/p/5148604.html
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