Question

我想编写一个搜索函数，该函数可以递归搜索数组并缩小每次迭代的结果。想法是找到第一组结果，然后继续该结果，然后再次搜索以找到下一组结果。搜索条件以带针的数组形式提供。我已经有一个基本的功能，但结果不符合预期。

我已经编写了运行的递归函数。但是迭代并没有给我我最终的结果。

$array = array(
    0 => array('id' => 1, 'currency' => 'EUR', 'name' => 'NL', 'country_code' => 31), 
    1 => array('id' => 2, 'currency' => 'EUR', 'name' => 'DE', 'country_code' => 49),
    2 => array('id' => 3, 'currency' => 'EUR', 'name' => 'FR', 'country_code' => 33),
    3 => array('id' => 4, 'currency' => 'EUR', 'name' => 'BE', 'country_code' => 32),
    4 => array('id' => 5, 'currency' => 'USD', 'name' => 'US', 'country_code' => 1),
    5 => array('id' => 6, 'currency' => 'Rand', 'name' => 'SAF', 'country_code' => 27),
    6 => array('id' => 7, 'currency' => 'Rubbles', 'name' => 'RUS', 'country_code' => 7),
    7 => array('id' => 8, 'currency' => 'EUR', 'name' => 'IT', 'country_code' => 39),
    8 => array('id' => 9, 'currency' => 'Pound', 'name' => 'GB', 'country_code' => 44),
); //list of countries which needs to searched

$query = array('currency' => 'EUR', 'id' => 8, 'country_code' => 49); //search needles

function _searchData(array $array, array $query, $counter=0) 
{
  $result = array();
  $matches_found = array();

  if($array){
     $i = $counter; //set counter, start with 0
     $keys = array_keys($query); //get query keys
     $vals = array_values($query); //get query values
     $max = count($keys); //set max_count to limit iteration

     foreach($array as $arrkey => $arrval){
       if(isset($arrval[$keys[$i]]) && $arrval[$keys[$i]] == $vals[$i] && $i < $max){ 
         $matches_found = $this->_searchData($arrval, $query, $i++); //return result, increment counter
         if($matches_found){    
           $arrval = $matches_found; //overwrite result array           
          }
       $result[] = $arrval;  
     }
   }
  return $result;
}
Expected result = 
**it should fail on the 3rd iteration because "country_code" does not match 
on result id 8.

我认为我的主要问题是计数器，因为它需要增加。在foreach循环中，我无法完全控制。我尝试存储matchs_found并在循环外重新使用它，但这也不起作用。

该函数的目标是缩小每次迭代的结果，以最终结果集结尾，因为它与较少的键值对匹配。 Ps也许有一种更简单的方法来搜索带有大量指针的数组，而且我总是愿意接受其他建议，但是我的主要目标是使此递归函数正常运行，因为这对我来说最有意义的是实现我的期望结果。同样，在灵活性方面，我可以根据需要拥有任意数量的搜索针。我希望有人能给我正确的方向。预先感谢！

Answer 1

我认为您可以根据自己的要求做很多简单的事情，例如：

<?php

$in = [
    ['id' => 1, 'currency' => 'EUR',     'name' => 'NL'],
    ['id' => 2, 'currency' => 'EUR',     'name' => 'DE'],
    ['id' => 3, 'currency' => 'EUR',     'name' => 'FR'],
    ['id' => 4, 'currency' => 'EUR',     'name' => 'BE'],
    ['id' => 5, 'currency' => 'USD',     'name' => 'US'],
    ['id' => 6, 'currency' => 'Rand',    'name' => 'SAF'],
    ['id' => 7, 'currency' => 'Rubbles', 'name' => 'RUS'],
    ['id' => 8, 'currency' => 'EUR',     'name' => 'IT'],
    ['id' => 9, 'currency' => 'Pound',   'name' => 'GB'],
];

$query = ['currency' => 'EUR', 'id' => 8]; //search needles

// array_filter will use the given callback to check every entry
$out = array_filter($in, function(array $candidate) use ($query) {
    // iterate over query
    foreach ($query as $key => $predicate) {
        // if the key exists, but the value differs
        if (isset($candidate[$key]) && $candidate[$key] !== $predicate) {
            // it should not be included
            return false;
        }
    }

    // otherwise, include
    return true;
});

print_r($out);

演示：Deploy the function app project to Azure

ref：https://3v4l.org/aAZPP

递归搜索功能可缩小每次迭代的结果

1 个答案: