Search for highest key/index in an array

问题:

How can I get with PHP the highest key/index in an array? I know how to do it for the values.

E.g. From this array I would like to get "10" as an integer value:

$arr = array( 1 => "A", 10 => "B", 5 => "C" );

I know how I could program it, but I was asking myself if there as a function for this as well.

回答1:

This should work fine

$arr = array( 1 => "A", 10 => "B", 5 => "C" );
max(array_keys($arr));

回答2:

You can get the maximum key this way:

<?php
$arr = array("a"=>"test", "b"=>"ztest");
$max = max(array_keys($arr));
?>

回答3:

$keys = array_keys($arr);
$keys = rsort($keys);

print $keys[0];

should print "10"

回答4:

Try max(): http://php.net/manual/en/function.max.php See the first comment on that page