In terms of my data structure, I have an array of communications, with each communications_id itself containing three pieces of information: id, score, and content.
I want to implode this array in order to get a comma separated list of ids, how do I do this?
PHP 5.5 introduces array_column which is a convenient shortcut to a whole class of array_map usage; it is also applicable here.
$ids = array_column($communications, 'id');
$output = implode(',', $ids);
You need to make an array of just ids out of your array of communications. Then the implode would be trivial.
Hint: the function for that is array_map.
Solution:
Assumes PHP 5.3, otherwise you 'd have to write the callback as a string.
$ids = array_map(function($item) { return $item['id']; }, $communications);
$output = implode(',', $ids);
$communications, as it is being passed to the callback function for mapping to something else. It's just the name of a formal parameter; you can use any other name just as well.$firstN = array_slice($allOfThem, 0, $n);. The PHP array functions are extremely useful and versatile. Spend some time to familiarize yourself with them: php.net/manual/en/ref.array.php.You can have a look to array_walk_recursive function . This is a working snippet of creating of recursive array to string conversion :
$array =
array(
"1" => "PHP code tester Sandbox Online",
"foo" => "bar",
5 ,
5 => 89009,
"case" => "Random Stuff",
"test" =>
array(
"test" => "test221",
"test2" => "testitem"
),
"PHP Version" => phpversion()
);
$string="";
$callback =
function ($value, $key) use (&$string) {
$string .= $key . " = " . $value . "\n";
};
array_walk_recursive($array, $callback);
echo $string;
## 1 = PHP code tester Sandbox Online
## foo = bar
## 2 = 5
## 5 = 89009
## case = Random Stuff
## test = test221
## test2 = testitem
## PHP Version = 7.1.3
From http://snipplr.com/view.php?codeview&id=10187:
class Format {
static public function arr_to_csv_line($arr) {
$line = array();
foreach ($arr as $v) {
$line[] = is_array($v) ? self::arr_to_csv_line($v) : '"' . str_replace('"', '""', $v) . '"';
}
return implode(",", $line);
}
static public function arr_to_csv($arr) {
$lines = array();
foreach ($arr as $v) {
$lines[] = self::arr_to_csv_line($v);
}
return implode("\n", $lines);
}
}
For anyone else looking for an answer, this is what I was able to do:
$singleDimensionalArray = array();
foreach($array["1"]["2"]["3"][...] as $value) {
$singleDimensionalArray[] = $value;
}
I used this with a 3-dimensional array.
this comment based on @jon solution , just add functional code block
but i have to use loop because array_map does not accept second parameter
function array_column_implode($data_array = array(),$key = 'id', $delimiter = ',')
{
if (function_exists('array_column'))
{
return implode($delimiter, array_column($data_array, $key));
}
else
{
$new_data_array = array();
foreach ($data_array as $value) {
if (isset($value[$key]))
{
$new_data_array[] = $value[$key];
}
}
return implode($delimiter, $new_data_array);
}
}
