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Php removes the duplicate data: 1, remove the duplicate data in the one-dimensional array through the array_unique function; 2, remove the duplicate data in the multi-dimensional array through the custom unique_arr method.

This article operating environment: Windows7 system, PHP7.1 version, DELL G3 computer

How does php remove duplicate data?

PHP removes duplicate array data

There is a built-in function array_unique () for removing duplicates in PHP array, but the array_unique function of php is only suitable for one-dimensional array, but not for multi-dimensional array. Here is an array_unique function of two-dimensional array.

Function unique_arr ($array2D,$stkeep=false,$ndformat=true) {/ / determine whether to retain the first-order array key (the first-order array key can be non-numeric) if ($stkeep) $stArr = array_keys ($array2D); / / determine whether to retain the secondary array key (all secondary array keys must be the same) if ($ndformat) $ndArr = array_keys (end ($array2D)) / / Dimension reduction, or you can use implode to convert an one-dimensional array to a comma concatenated string foreach ($array2D as $v) {$v = join (",", $v); $temp [] = $v;} / / remove the duplicate string, that is, the repeating one-dimensional array $temp = array_unique ($temp) / then reassemble the disassembled array foreach ($temp as $k = > $v) {if ($stkeep) $k = $stArr [$k]; if ($ndformat) {$tempArr = explode (",", $v); foreach ($tempArr as $ndkey = > $ndval) $output [$k] [$ndArr [$ndkey]] = $ndval;} else $output [$k] = explode (",", $v);} return $output }

Demo:

$array2D = array ('first'= > array (' title'= > '1111),' second'= > array ('title'= >' 1111), 'third'= > array (' title'= >'22')); print_r ($array2D); print_r (unique_arr ($array2D,true))

Method 2:

Example 1

First, the PHP one-dimensional array removes duplicates (using the array_unique function).

Example 1, code:

Output result:

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

Second, duplicates of the PHP two-dimensional array:

For the two-dimensional array, we discuss it in two cases, one is because the value of a key name cannot be duplicated, delete the duplicate item.

The other removes duplicates because the internal one-dimensional array cannot be exactly the same.

Example 1, because the value of a key name cannot be duplicated, delete the duplicate item.

Code:

Output result:

Array ([0] = > Array ([id] = > 123 [name] = > Zhang San) [1] = > Array ([id] = > 124 [name] = > Wang Wu) [2] = > Array ([id] = > 125 [name] = > Zhao Liu) [3] = > Array ([id] = > 126 [name] = > Zhao Liu))

In example 2, duplicates are deleted because the internal one-dimensional array cannot be exactly the same.

Code:

Array ([0] = > Array ([0] = > 123 [1] = > Zhang San) [1] = > Array ([0] = > 123 [1] = > Li Si) [2] = > Array ([0] = > 124 [1] = > Wang Wu) [4] = > Array ([0] = > 126 [1] = > Zhao Liu)) what are the php frameworks of php: 1. Laravel,Laravel is a free and open source PHP application framework. 2. Phalcon,Phalcon is the fastest PHP framework. 3. Symfony,Symfony is a PHP framework for Web projects. 4. Yii,Yii is a fast, secure and professional PHP framework. CodeIgniter,CodeIgniter is a very agile open source PHP framework. 6. CakePHP,CakePHP is an old PHP framework. 7. Kohana recorder Kohana is an agile but powerful PHP framework.

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