使用extract检索多个数组值

时间:2012-11-27 14:20:55

标签: cakephp

array(
    [0]=>
        [index1]=>something
        [index2]=>something else
        [index3]=>something more
    [1]=>
        [index1]=>something
        [index2]=>something else
        [index3]=>something more
    [2]=>
        [index1]=>something
        [index2]=>something else
        [index3]=>something more
)

编辑: 所以我想检索以下内容:

array(
    [0]=>
        [index1]=>something
        [index2]=>something else
    [1]=>
        [index1]=>something
        [index2]=>something else
    [2]=>
        [index1]=>something
        [index2]=>something else
)

如何使用cakephp中的Set :: extract函数获取数组的多个索引?

这将检索一个值:

Set::extract($array, '{n}.index1');

但我希望获得多个值...比如,index1和index2。

我尝试了以下的陈述,但没有用。

Set::extract($array, '[{n}.index1, {n}.index2']);

修改

    $__pages = Hash::merge(
                    Hash::extract($pages, 'pages.{n}.id'),
                    Hash::extract($pages, 'pages.{n}.title')
                    );
    pr($__pages);

输出:

Array
(
    [0] => 2
    [1] => 4
    [2] => 104
    [3] => Sample Page
    [4] => about us
    [5] => Services
)

这对我没有帮助,因为我仍然需要这样的关联:

Array(
   [2] => Sample Page
   [4] => About us
   [104] => Services
)

我甚至会满意:

Array(
   Array(id => 2, title => Sample Page)
   Array(id => 4, title => About Us)
   Array(id => 104, title => Services)
)

ANSWER thecodeparadox的答案适用于我提供的测试代码。这是现实生活中的代码,以防有人在这里绊倒。 它在书中指出,“除{n}和{s}之外的括号中的任何字符串文字都被解释为正则表达式。” 这条线似乎是隐藏的,而不是非常明显。所以知道这一点,我只是使用正则表达式规则来检索我需要的数据。我有一个数组从api中提取wordpress帖子,我需要将结果缩小到id, title

array(
   posts=>
      0=>
         id => 3
         slug => sample-page
         type => page
         title => Sample Page
         //...and so on 

      1=>
         id => 7
         slug => sample-page-2
         type => page
         title => Sample Page 2
         //...and so on 

为了只检索id和标题,我添加了以下行。

pr(Set::classicExtract($pages, 'pages.{n}.{(id|title)}'));
这给了我:

array(
   posts=>
      0=>
         id => 3
         title => Sample Page

      1=>
         id => 7
         title => Sample Page 2

文件:Book

6 个答案:

答案 0 :(得分:6)

$arr = array(
            array(
                'index1'=>'something',
                'index2'=>'something else',
                'index3'=>'something more',
            ),
            array(
                'index1'=>'something',
                'index2'=>'something else',
                'index3'=>'something more',
            ),
            array(
                'index1'=>'something',
                'index2'=>'something else',
                'index3'=>'something more',
            )
        );

$output = Set::classicExtract($arr, '{n}.{index[1-2]}');

print_r($output);

// output


Array
(
    [0] => Array
        (
            [index1] => something
            [index2] => something else
        )

    [1] => Array
        (
            [index1] => something
            [index2] => something else
        )

    [2] => Array
        (
            [index1] => something
            [index2] => something else
        )

)

答案 1 :(得分:1)

您是否尝试过Set :: extract($ array,'{n}。{s}'); ?

编辑:如果您的数组维度与答案中的数组完全相同,则可以尝试使用array_keys(Set :: extract($ array,'{n}。{s}'));

答案 2 :(得分:1)

一种方式(如果你只想保留一些结果):

Hash::merge(
    Hash::extract($array, '{n}.index1'),
    Hash::extract($array, '{n}.index2')
);

另一种方式(如果你只想删除一些):

Hash::remove($array, '{n}.index3');

答案 3 :(得分:1)

我不确定你为什么要坚持使用Set课程?如果它不适合您的需要,为什么你绝对使用它而不是创建自己的功能? 您在其中一条评论中表示要避免foreach循环。但是Set类方法充满了foreach个循环。我可能会错过这一点......

Personnaly我会简单地用这样的函数来做:

function filter_fields($array_to_filter, $fields_to_keep)
{
    foreach($array_to_filter as $i => $sub_array)
    {
        foreach($sub_array as $field => $value)
        {
            if(!in_array($field, $fields_to_keep))
            {
                unset($array_to_filter[$i][$field]);
            }
        }
    }

    return $array_to_filter;
}

以下是它将返回的示例:

print_r($array_to_filter);
/*
Array
(
    [0] => Array
        (
            [index1] => abc
            [index2] => def
            [index3] => ghi
        )

    [1] => Array
        (
            [index1] => jkl
            [index2] => mno
            [index3] => poq
        )
)
*/

$filtered_array = filter_fields($array_to_filter, array('index1', 'index3'));

print_r($filtered_array);
/*
Array
(
    [0] => Array
        (
            [index1] => abc
            [index3] => ghi
        )

    [1] => Array
        (
            [index1] => jkl
            [index3] => poq
        )
)
*/

答案 4 :(得分:1)

设置真棒!你不能直接使用Set :: extract来做这个,但你可以使用Set :: combine来构建两个数组索引的关联数组:

Set::combine($myArray, '{n}.index1', '{n}.index2')

一个工作示例如下所示:

$myArray = array(
    array('index1'=>'something 1', 'index2'=>'something else 1', 'index3'=>'something more 1'),
    array('index1'=>'something 2', 'index2'=>'something else 2', 'index3'=>'something more 2'),
    array('index1'=>'something 3', 'index2'=>'something else 3', 'index3'=>'something more 3'),
);

debug(Set::combine($myArray, '{n}.index1', '{n}.index2'));

这将采用您提到的数组:

array(
[0]=>
    [index1]=>something 1
    [index2]=>something else 1
    [index3]=>something more 1
[1]=>
    [index1]=>something 2
    [index2]=>something else 2
    [index3]=>something more 2
[2]=>
    [index1]=>something 3
    [index2]=>something else 3
    [index3]=>something more 3

并将其转换为:

Array (
    [something1] => something else 1
    [something2] => something else 2
    [something3] => something else 3
)

答案 5 :(得分:1)

[+10]在这篇文章中向我揭示了classicExtract方法的大拇指。

示例数组:

$params = array(
  'key-1'=>array('subkey'=>array('x'), 'junk'), 
  'key-2'=>array('subkey'=>array('y'), 'otherkey'=>'more junk')
);

我遇到的问题:

基本密钥转换为int。

 eg. array(0=>array('x'), 1=>array('y'))

解决方案:

$array = Hash::filter(Set::classicExtract($params, '{[a-zA-Z0-9-_.]}.subkey'));

返回:

eg. array('key-1'=>array('x'), 'key-2'=>array('y'))

根据需要在密钥中修改正则表达式。

刚刚写了这个函数

它将使用{a)代替{s}

来解析数组

{a}表示基础的关联键。

这样调用:static :: extract($ array,'{a} .subkey');

  public static function extract($array, $path, $filter=true){
    $path = str_replace("{a}", "{[a-zA-Z0-9-_.]}", $path);
    if(is_array($array)){
      $return = Set::classicExtract($array, $path);
      if($filter){
        if(is_array($return)){
          $return = Hash::filter($return);
        }
      }
      return $return;
    }
  }

[[蛋糕3的更新]]

如果您使用此功能,我看到cakephp刚删除了set类。您可以通过将classicExtract方法添加到类

来再次使用它
use Cake\Utility\Hash;

public static function classicExtract($data, $path = null)
{
    if (empty($path)) {
        return $data;
    }
    if (is_object($data)) {
        if (!($data instanceof \ArrayAccess || $data instanceof \Traversable)) {
            $data = get_object_vars($data);
        }
    }
    if (empty($data)) {
        return null;
    }
    if (is_string($path) && strpos($path, '{') !== false) {
        $path = \Cake\Utility\String::tokenize($path, '.', '{', '}');
    } elseif (is_string($path)) {
        $path = explode('.', $path);
    }
    $tmp = array();

    if (empty($path)) {
        return null;
    }

    foreach($path as $i => $key) {
        if (is_numeric($key) && intval($key) > 0 || $key === '0') {
            if (isset($data[$key])) {
                $data = $data[$key];
            } else {
                return null;
            }
        } elseif ($key === '{n}') {
            foreach($data as $j => $val) {
                if (is_int($j)) {
                    $tmpPath = array_slice($path, $i + 1);
                    if (empty($tmpPath)) {
                        $tmp[] = $val;
                    } else {
                        $tmp[] = static::classicExtract($val, $tmpPath);
                    }
                }
            }
            return $tmp;
        } elseif ($key === '{s}') {
            foreach($data as $j => $val) {
                if (is_string($j)) {
                    $tmpPath = array_slice($path, $i + 1);
                    if (empty($tmpPath)) {
                        $tmp[] = $val;
                    } else {
                        $tmp[] = static::classicExtract($val, $tmpPath);
                    }
                }
            }
            return $tmp;
        } elseif (strpos($key, '{') !== false && strpos($key, '}') !== false) {
            $pattern = substr($key, 1, -1);

            foreach($data as $j => $val) {
                if (preg_match('/^'.$pattern.'/s', $j) !== 0) {
                    $tmpPath = array_slice($path, $i + 1);
                    if (empty($tmpPath)) {
                        $tmp[$j] = $val;
                    } else {
                        $tmp[$j] = static::classicExtract($val, $tmpPath);
                    }
                }
            }
            return $tmp;
        } else {
            if (isset($data[$key])) {
                $data = $data[$key];
            } else {
                return null;
            }
        }
    }
    return $data;
}

//CAKEPHP METHODS
public static function extract($array, $path, $filter = true)
{
    $return = [];
    if (is_array($array)) {
        if (stristr($path, '{a}')) {
            $return = static::classicExtract($array, str_replace("{a}", "{[a-zA-Z0-9-_. ]}", $path));
        } else {
            $return = Hash::extract($array, $path);
        }
    }
    if ($filter && is_array($return)) {
        $return = Hash::filter($return);
    }
    return $return;
}