PHP returns the specified column in the array (php5.5.0 default function Array_column () in php<5.5.0 application)

Array_column () Returns the column of the specified key name in the array (PHP 5 >= 5.5.0) array_column-returns a column specified in the array PHP Reference Manual: http://www.php.net/manual/zh/function.array-column.php What if the PHP version is less than 5.5.0? We customize a The following code is excerpted from Onethink /** * Returns a column specified in the array * http://www.onethink.cn */application/common/common/function.php * * array_column-php 5 >= 5.5.0 default function * PHP 5 < 5.5.0 use custom functions * * @access Public * @param array $input a multidimensional array (or result set) that requires the array column to be fetched * @param string $columnKey A column that needs to return a value, which can be the column index of an indexed array, or the key of a column of an associative array. It can also be null, and this will return the entire array (which works well with the Indexkey parameter to reset the array key) * @param string $indexKey as the column that returns the index/key of the array, which can be an integer index of the column, or a string key value. * @return Array */ if (! function_exists (' Array_column ')) { function Array_column (array $input, $columnKey, $indexKey = null) { $result = Array (); if (null = = = $indexKey) { if (null = = = $columnKey) { $result = Array_values ($input); } Else { foreach ($input as $row) { $result [] = $row [$columnKey]; } } } Else { if (null = = = $columnKey) { foreach ($input as $row) { $result [$row [$indexKey]] = $row; } } Else { foreach ($input as $row) { $result [$row [$indexKey]] = $row [$columnKey]; } } } return $result; } } Copy Code Array representing a possible record set returned from a database $records = Array ( Array ' id ' = 2135, ' first_name ' = ' John ', ' last_name ' = ' Doe ', ), Array ' id ' = 3245, ' first_name ' = ' Sally ', ' last_name ' = ' Smith ', ), Array ' id ' = 5342, ' first_name ' = ' Jane ', ' last_name ' = ' Jones ', ), Array ' id ' = 5623, ' first_name ' = ' Peter ', ' last_name ' = ' Doe ', ) ); $first _names = Array_column ($records, ' first_name '); Print_r ($first _names); ?> Copy Code Array ( [0] = John [1] = Sally [2] = Jane [3] = Peter ) Copy Code

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