我从Web服务中提取了大量数据，这使我得到了一个多维混合数组，其中我只需要10％的信息。 我正在寻找一种灵活的方式来保留我的目的所需的信息。
我没有找到PHP函数或方法来做到这一点。
不要误解我的意思，我不想过滤价值观，我也不想对元素进行切片。
将其置于数据库视角，我想＆＃34;简单地＆＃34;删掉一些列。或者更好：我想保留我需要的列，并删除所有其他我不需要的列表，我也不知道。
E.G。
$big_array = array(
array("year" => 1979, "name" => "Miller", "wage" => "100", "children"=>array("John", "Kate")),
array("year" => 1983, "name" => "Smith", "wage" => "200"),
array("year" => 1980, "name" => "Mayer", "wage" => "200", "children"=>array("Tom")),
array("year" => 1981, "name" => "Mayer", "wage" => "100"),
array("year" => 1980, "name" => "Clinton", "wage" => "300", "children"=>array("Rosa", "Dick", "Christine")),
array("year" => 1981, "name" => "Bush", "wage" => "200"));
print_r($big_array);
会给我这个：
Array
(
[0] => Array
(
[year] => 1979
[name] => Miller
[wage] => 100
[children] => Array
(
[0] => John
[1] => Kate
)
)
[1] => Array
(
[year] => 1983
[name] => Smith
[wage] => 200
)
[2] => Array
(
[year] => 1980
[name] => Mayer
[wage] => 200
[children] => Array
(
[0] => Tom
)
)
[3] => Array
(
[year] => 1981
[name] => Mayer
[wage] => 100
)
[4] => Array
(
[year] => 1980
[name] => Clinton
[wage] => 300
[children] => Array
(
[0] => Rosa
[1] => Dick
[2] => Christine
)
)
[5] => Array
(
[year] => 1981
[name] => Bush
[wage] => 200
)
)
现在出现了问题。我不知道我得到了哪些额外信息，因为我不是网络服务的主人。我只知道我需要的列。在这种情况下，我只需要＆＃34; name＆＃34;和＃34;孩子＆＃34;。而且我不想因为没有孩子而丢失数组元素。
因此返回的数组应如下所示：
Array
(
[0] => Array
(
[name] => Miller
[children] => Array
(
[0] => John
[1] => Kate
)
)
[1] => Array
(
[name] => Smith
)
[2] => Array
(
[name] => Mayer
[children] => Array
(
[0] => Tom
)
)
[3] => Array
(
[name] => Mayer
)
[4] => Array
(
[name] => Clinton
[children] => Array
(
[0] => Rosa
[1] => Dick
[2] => Christine
)
)
[5] => Array
(
[name] => Bush
)
)
因此该函数看起来像这样：
$small_array=function($big_array, array("name","children"));
第二个参数包含要保留的键/列数组。
有什么想法吗？
答案 0 :(得分：2)
试试这个：
$big_array = array(
array("year" => 1979, "name" => "Miller", "wage" => "100", "children"=>array("John", "Kate")),
array("year" => 1983, "name" => "Smith", "wage" => "200"),
array("year" => 1980, "name" => "Mayer", "wage" => "200", "children"=>array("Tom")),
array("year" => 1981, "name" => "Mayer", "wage" => "100"),
array("year" => 1980, "name" => "Clinton", "wage" => "300", "children"=>array("Rosa", "Dick", "Christine")),
array("year" => 1981, "name" => "Bush", "wage" => "200"));
$reqField = array('name','children');
$a = optimizeArray($big_array,$reqField);
echo "<pre>";
print_r($a);
function optimizeArray($big_array,$reqField)
{
$retArr = array();
foreach($big_array as $mk=>$arr)
{
foreach($arr as $k=>$v)
{
if(in_array($k,$reqField) && isset($arr[$k]))
{
$retArr[$mk][$k] = $v;
}
}
}
return $retArr;
}
答案 1 :(得分：1)
您可以尝试此功能 -
$small_array = factor_array($big_array, array("name","children"));
/*
$main the big array
$keys the indexes to be extracted
*/
function factor_array($main, $keys) {
$temp = array();
//loop through the big array
foreach($main as $index => $array) {
// loop through the keys array
foreach($keys as $key) {
if(isset($array[$key])) {// check if the key is set
$temp[$index][$key] = $array[$key]; // store with the key
}
}
}
return $temp;
};
答案 2 :(得分：0)
好的，这两个答案对我的问题都是正确的。我要感谢你们俩。 但经过测试后，我意识到还有更深层的数组元素。 所以我想我们需要一个迭代的，递归的解决方案，这远远超出我的知识。
我得到了
$big_array = array(
array("year" => 1979, "name" => "Miller", "wage" => "100", "children"=>array("John", "Kate")),
array("year" => 1983, "name" => "Smith", "wage" => "200"),
array("year" => 1980, "name" => "Mayer", "wage" => "200", "children"=>array("Tom")),
array("year" => 1981, "name" => "Mayer", "wage" => "100"),
array("year" => 1980, "name" => "Clinton", "wage" => "300", "children"=>array("Rosa"=>array("Pet"=>array("Clover")), "Dick", "Christine")),
array("year" => 1981, "name" => "Bush", "wage" => "200"));
print_r($big_array);
给我
Array
(
[0] => Array
(
[name] => Miller
[children] => Array
(
[0] => John
[1] => Kate
)
)
[1] => Array
(
[name] => Smith
)
[2] => Array
(
[name] => Mayer
[children] => Array
(
[0] => Tom
)
)
[3] => Array
(
[name] => Mayer
)
[4] => Array
(
[name] => Clinton
[children] => Array
(
[Rosa] => Array
(
[Pet] => Array
(
[0] => Clover
)
)
[0] => Dick
[1] => Christine
)
)
[5] => Array
(
[name] => Bush
)
)
如何优化甚至多维数组呢？
答案 3 :(得分：0)
这是一个非常简单的操作：使用array_intersect_key将单个数组减少到仅指定的键，然后对数组中的所有数组执行此操作：
$reduced = array_map(function (array $data) {
return array_intersect_key($data, array_flip(['name', 'children']));
}, $originalArray);