Get keys of an array where values is not NULL in PHP - php

Question

I have an associative array in PHP
$a = array("d1" => "data", "d2" => NULL, "d3" => "data")
I want to get all keys and all values which are not NULL, in order to implode them:
// e.g.:
$sub_key = array_keys($a, keys != NULL);
$sub_values = array_values($a, values != NULL);
echo "`".implode("`,`", $sub_key)."`";
echo "'".implode("','", $sub_key)."'";
Are there functions like array_keys() and array_values() that allow to take only vales that do not match the pattern?

Answer 1

Use array_filter before using array_keys and filter the array like this
$newArray = array_filter($a);
Then do
$sub_key = array_keys($newArray);
$sub_values = array_values($newArray);

Answer 2

You could use array_filter($a), but as one of the comments above pointed out, this would also filter out values like FALSE, empty strings, etc. So I'd use a foreach loop.
$new_array = array();
foreach ($a as $key => $value) {
if (is_null($value) === false) {
$new_array[$key] = $value;
}
}

Answer 3

Please try this:
// Loop to find empty elements and
// unset the empty elements
foreach($array as $key => $value)
if(empty($value))
unset($array[$key]);
// Display the array elements
foreach($array as $key => $value)
echo ($array[$key] . "<br>");
In you case you will replace $array with $a. This will work for null/empty key values.

Answer 4

$a = array("d1" => "data1", "d2" => NULL, "d3" => "data3");
$b = array_filter($a); // Not Null Values Array
$sub_key = array_keys(array_filter($a));
$sub_values = array_values(array_filter($a));
echo "`".implode("`,`", $sub_key)."` <br/>";
echo "'".implode("','", $sub_values)."'";

Answer 5

$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?