PHP obtains an instance of a specified column in the array and an instance of a column in the php array.

PHP obtains an instance of a specified column in the array and an instance of a column in the php array.

For a multi-dimensional array (taking a two-dimensional array as an example), you often need to obtain a column. For example, there are several pieces of user data, which is a two-dimensional array, now you need to get the names of these users. There are multiple methods to achieve this:

$arr = array(array('id'=>'101','name'=>'qu','age'=>28),array('id'=>'102','name'=>'you','age'=>24),array('id'=>'103','name'=>'zheng','age'=>22),array('id'=>'104','name'=>'zhu','age'=>23));

Method 1: Use the PHP built-in function array_column () to implement

array array_column ( array $input , mixed $column_key [, mixed $index_key ] ) 

Execute the statement:

$result = array_column($arr,'name')； print_r($result); 

The result is as follows:

Array (  [0] => qu  [1] => you  [2] => zheng  [3] => zhu ) 

If index_key is specified, the value of this column in the input array is used as the key to return the corresponding value in the array.

$result = array_column($arr,'name','id'); print_r($result); 

The result is as follows:

Array (  [101] => qu  [102] => you  [103] => zheng  [104] => zhu ) 

Method 2: Use the PHP built-in function array_map () to implement

array array_map ( callable $callback , array $arr1 [, array $... ] ) 

Array_map () returns an array that contains all the elements in arr1 that have passed the callback function. The first parameter is a callback function, and the returned value is an array. Each element of the array is processed by the callback function (callback) for each element in the array (arr1.

Declare a processing function first:

function get_val($arr){  return $arr['name']; } 

Then act on the array_map () function:

$result = array_map('get_val',$arr); print_r($result); 

The execution result is as follows:

Array (  [0] => qu  [1] => you  [2] => zheng  [3] => zhu ) 

Here, the first parameter of array_map () is a callback function, which is a well-known function defined in advance. Here we can also use an anonymous function like js:

$result = array_map(function($v){  return $v['name']; },$arr); 

The execution results are the same.

The above PHP obtains all the content shared by the editor in the array. I hope you can give us a reference and support the house of friends.