How do I get the value of a specified key from multiple keys in a two-dimensional array?

EssenceLOVEME962016-10-21 10:40:19 browse (1512) Answer (3) like (0)

Novice to ask: two-dimensional array will generally have more than one key, if we want to get the value of the specified key, what should be done?

Question label:PHP Answer (3)Timberswift 2016-10-21

The first: The simplest method: The foreach traversal array, the code:

foreach ($arr as $key => $value) {$arr2[] = $value[‘name‘];}

Another method: Using the Array_map $arr 2 = array_map (' Array_shift ', $arr); Moves the value of the beginning of each value of the $arr array out and returns the value that is moved out of each item value, noting that the key of the new array $arr2 is still the key of the original array $arr.

You can also do this if you need to get the beginning or end column of each item of a two-dimensional array: $arr 2 = array_map (' End ', $arr); Haha, is also very convenient.

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The third method: The Array_reduce method, but the code is slightly more, but this method of the imaginary space (for other array value operation) is still quite large:

$arr2 = array_reduce($arr, create_function(‘$result, $v‘, ‘$result[] = $v["name"];return $result;‘));

The Array_reduce method uses the callback function to iterate over the value of the array, and create_function is used for an anonymous method to call back, the parameter of the anonymous method $result the value generated for the last iteration, $v is the current value, and the internal implementation is both getting to the array $ The value of "name" for each entry of ARR and push to the new $result array;

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Fourth: This method is also very simple, and the most flexible

$arr2 = array_column($arr, ‘name‘);

The second parameter is the key name of the column you want to get, is not very convenient, but this method has a limitation, that is, PHP version must >= 5.5.0, use this method in a stale project or you have to think about it. Gets a value in a two-dimensional array randomly.

$arr 1 =Array (<span style="White-space:pre" > </span>' P1 ' =Array' Ky_d ' =' Quanzhou Fengze District, Fujian Province, China 1 ', ky_s ' => ' 350503005 '),  <span style=" White-space:pre "> </span> ' P2 ' => Array ( ' ky_d ' => ' Fujian Quanzhou Fengze District hua da Jie 2 ',  ky_s ' => ' 350503006 '),  <span style=" White-space:pre "> </span> ' P3 ' => Array ( ' ky_d ' => ' Fujian Quanzhou Fengze District hua da Jie 3 ',  ky_s ' => ' 350503007 ')); $temp = Array_rand ($arr 1,1);           

Gets all values for a particular key (array subscript) of a one-dimensional or multidimensional array.

author:[email protected]sina.cn description:

Take out all the values of a one-dimensional or multidimensional array based on a particular key (subscript), instead of looping, consider the efficiency of a large array, serialize the array, and extract the required strings based on the characteristics of the serialization structure.

functionArray_get_by_key(array $array, $string) {<span style="White-space:pre" > </span>if (!trim ($string))ReturnFalse;<span style="White-space:pre" > </span>preg_match_all ("/\" $string \ "; \w{1}:(?: \ d+:|) (. *);/", Serialize ($array), $res); <span style="White-space:pre" > </span>return $res [1];} $r =array ( ' id ' = 1,  ' s ' =" 23,  ' a ' = array ( ' s ' = 123, array (1, 2,  ' s ' = =  "ASDASDGSADGGSADG")); echo  ' <pre> ';p rint_r (Array_get_by_key ($r, /*result:array (<span style= "White-space:pre" > </span>[0] = 23<span style= "White-space:pre" > </span>[1] + 123<span style= "White-space:pre" > </span>[2] = " ASDASDGSADGGSADG ") */             

How can I get the value of a specified key from multiple keys in a two-dimensional array?