如何收集数组中所有真值的键？

Question

This is slightly modified version of the code in the PHP docs:

http://php.net/manual/en/function.next.php

<?php

$array = array(
    -1 => true,
    0 => false,
    1 => true
);

while ($bet = current($array)) {
    if ($bet == true) {
        echo key($array) . '<br />';
    }
    next($array);
}
?>

This is as close as I could get to what I wanted.

This this echoes "-1", and I DO understand why.

What I want to know is how to modify this code so that it will continue searching for "true" values even after it encounters an false (and not just for an array of 3 values).

I realize this might not be the best way of doing it and I am open to suggestions.

Thanks in advance!!

Trufa

Answer 1

echo join("<br>", array_keys(array_filter($array)));

array_filter returns true values when you don't supply a callback method, array_keys gets you the keys for those values, then prep it for output using join