Get key from an array in smarty - php

Question

If I have an array that looks like this:
$my_array = array(2) { ["mykey"]=> int(2) ["mysecondkey"]=> int(3) }
How can I get to the key value of the first element?.
So far I know I can do $my_array[0], but how do I get to the first key? I want to avoid doing foreach.
Thanks!

Answer 1

This is associative array (string keys). Use name of key directly:
$my_array["mykey"];
Read more here
To extract keys use array_keys:
$my_array = array(2) { ["mykey"]=> int(2) ["mysecondkey"]=> int(3) }
$keys = array_keys($my_array); //0 => "mykey", 1 => "mysecondkey"

Answer 2

You can use array_keys() to get a list of your array's keys:
$keys = array_keys($my_array);
echo $keys[0]; // outputs "mykey"
If you want to do this in Smarty, you can use the following code to output the array's first key:
{foreach from=$my_array key=my_key item=i name=my_array}
{if $smarty.foreach.my_array.first}{$my_key}{/if}
{/foreach}

Answer 3

foreach($my_array as $key=>$_val){
echo $key;
break;
}

Answer 4

array_keys() will get all the keys in an array, while this will get the first key without iterating all the others and ignoring the rest of the array.
It is a fake loop as the break will exit at the first iteration, so you are not actually doing a real foreach for all the values.
foreach($my_array as $firstKey=>$unused) {
break;
}
echo($firstKey);
If you need a function, you may use this:
function first_key($arr) {
foreach($my_array as $firstKey=>$unused) {
return $firstKey;
}
}
Again the function returns at the first iteration, so you are not doing a "real" foreach on all the elements.