Simplify a multidimensional array to a string [duplicate]

Question

I have this kind of array in my $tag variable.

Array
(
    [0] => Array
        (
            [tag_name] => tag-1
        )
    [1] => Array
        (
            [tag_name] => tag-2
        )
    [2] => Array
        (
            [tag_name] => tag-3
        )
)

What I'm trying to do is get all the tag names and implode them with a coma then make it a value for a text input field.

I've tried for and foreach loops so many different ways but with not much success. I'm using CodeIgniter if that helps.

Answer 1

You can use array_column followed by join or implode

Try this :

$string = join(',', array_column($array, 'tag_name'));

Explanation:

array_column returns the values from a single column from the input array

For your array, array_column($array 'tag_name') returns an array containing values of index tag_name, i.e returned array would be :

Array
(
    [0] => tag-1
    [1] => tag-2
    [2] => tag-3
)

Joining with join or implode , you get your desired string,

//$string = "tag-1,tag-2,tag-3"

Answer 2

A simple and obvious solution might be:

$res = "";
for ($i = 0; $i < count($tag); $i++) {
    $res .= $tag[$i]["tag_name"] . ",";
}
$res = trim($res, ","); //Removing the extra commas
echo $res;

You basically iterate through the array, and every element you iterate through, you add it's tag_name to a $res string.