PHP数组。基于键的简单拆分

This is more a request for a quick piece of advice as, I find it very hard to believe there isn't a native function for the task at hand. Consider the following:

这更像是对快速建议的要求,因为我发现很难相信手头的任务没有本地功能。考虑以下:

array => 
(0) => array("id" => "1", "groupname" => "fudge", "etc" => "lorem ipsum"),
(1) => array("id" => "2", "groupname" => "toffee", "etc" => "lorem ipsum"),
(2) => array("id" => "3", "groupname" => "caramel", "etc" => "lorem ipsum")
)

What I am looking to get is a new array which uses only "groupname" so would equal:

我期待得到的是一个新的数组,它只使用“groupname”,所以会相等:

array =>
(0) => "fudge",
(1) => "toffee",
(2) => "caramel"
)

I know this is very simple to achieve recursively going through the original array, but I was wondering if there is a much simpler way to achieve the end result. I've looked around the internet and on the PHP manual and can't find anything

我知道实现递归遍历原始数组非常简单,但我想知道是否有更简单的方法来实现最终结果。我环顾了互联网和PHP手册,找不到任何东西

Thank you kindly for reading this question Simon

谢谢你好好读这个问题西蒙

6 个解决方案

#1

If you are using PHP 5.3, you can use array_map ^[docs] like this:

如果您使用的是PHP 5.3,则可以像这样使用array_map [docs]:

$newArray = array_map(function($value) {
    return $value['groupname'];
}, $array);

Otherwise create a normal function an pass its name (see the documentation).

否则创建一个普通函数并传递其名称(请参阅文档)。

Another solution is to just iterate over the array:

另一种解决方案是迭代数组:

$newArray = array();

foreach($array as $value) {
    $newArray[] = $value['groupname'];
}

You definitely don't have to use recursion.

你绝对不必使用递归。

#2

There is a native array_column() function exactly for this (since PHP 5.5):

完全有一个本机array_column()函数(从PHP 5.5开始):

$column = array_column($arr, 'groupname');

#3

Use array_map:

<?php
$a = array(
    array("id" => "1", "groupname" => "fudge", "etc" => "lorem ipsum"),
    array("id" => "2", "groupname" => "toffee", "etc" => "lorem ipsum"),
    array("id" => "3", "groupname" => "caramel", "etc" => "lorem ipsum")
);

function get_groupname( $arr )
{
    return $arr['groupname'];
}
$b = array_map( 'get_groupname', $a );

var_dump( $a );
var_dump( $b );

http://codepad.org/7kNi8nNm

#4

Values by all array keys:

所有数组键的值:

$array = [
    ["id"=>"1","user"=>"Ivan"],
    ["id"=>"2","user"=>"Ivan"],
    ["id"=>"3","user"=>"Elena"]
    ];

$res = [];
$array_separate = function($value, $key) use (&$res){
    foreach($value AS $k=>$v) {
        $res[$k][] = $v;
    }
};

array_walk($array, $array_separate);
print_r($res);

result:

Array
(
    [id] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
        )
    [user] => Array
        (
            [0] => Ivan
            [1] => Ivan
            [2] => Elena
        )

)

http://sandbox.onlinephpfunctions.com/code/3a8f443283836468d8dc232ae8cc8d11827a5355

#5

As far as I know there isn't a simple function in PHP that could handle this for you, the array structure is user-defined, you would have to loop through the array. The easiest way I can think of would be something like this:

据我所知,PHP中没有一个可以为你处理的简单函数,数组结构是用户定义的,你必须遍历数组。我能想到的最简单的方法是这样的:

for($i = 0;$i < count($main_array);$i++){
    $groupname_array[] = $main_array[$i]["groupname"];
}

#6

function array_get_keys(&$array, $key) {
    foreach($array as &$value) $value = $value[$key];
}
array_get_keys($array, 'groupname');

function array_get_keys(&$array, $key) {
    $result = Array();
    foreach($array as &$value) $result[] = $value[$key];
    return $result;
}
$new_array = array_get_keys($array, 'groupname');

#1