獲取一個陣列的鍵，其中值不爲NULL在PHP

Question

我在PHP

$a = array("d1" => "data", "d2" => NULL, "d3" => "data") 

關聯數組我想所有按鍵和所有非NULL值，以爆他們：

// e.g.: 
$sub_key = array_keys($a, keys != NULL); 
$sub_values = array_values($a, values != NULL); 

echo "`".implode("`,`", $sub_key)."`"; 
echo "'".implode("','", $sub_key)."'"; 

是否有功能，如array_keys()和array_values()，允許採取只做不匹配模式瓦萊斯？

Answer 1

使用array_filter使用array_keys和過濾陣列這樣

$newArray = array_filter($a); 

然後做

$sub_key = array_keys($newArray); 
$sub_values = array_values($newArray); 

Answer 2

你可以使用array_filter($a)，但作爲一個評論上文所指出的，這也將過濾器之前輸出值如FALSE，空字符串等，所以我會使用一個foreach循環。

$new_array = array(); 

foreach ($a as $key => $value) { 
    if (is_null($value) === false) { 
     $new_array[$key] = $value; 
    } 
} 

Answer 3

$sub_key = array(); 
$sub_values = array(); 
foreach ($a as $key => $value) { 
    if (!is_null($key) && !is_null($value)) { // you can also do is_empty() in stead of is_null() if you also wan't to avoid empty string 
     $sub_key[] = $key; 
     $sub_values[] = $value; // or use mysql_real_escape_string($value) if you are going to create a query with this! Otherwise you will create an SQL injection vulnerability here. 
    } 
} 

// you can add if(count($sub_key)) here to only do the echoes, if there was at least 1 item in the array. Otherwise you will echo an empty `` 
echo "`".implode("`,`", $sub_key)."`"; 
echo "'".implode("','", $sub_key)."'"; // don't you mean $sub_values here? 

與