[SR-Users] how can string "0" be equal to int 0?

[Juha Heinanen]

i have stored in htable a key_value=0 with key_type=1, i.e., string.

then i have this piece of test code:

    if (defined($sht(htable=>$var(carrier_key)::id))) {
        xlog("L_INFO", "$sht(htable=>$var(carrier_key)::id) is defined\n");
    } else {
        xlog("L_INFO", "$sht(htable=>$var(carrier_key)::id) is NOT defined\n");
    };
    $var(carrier_id) = $sht(htable=>$var(carrier_key)::id);
    if ($var(carrier_id) == (int)0) {
        xlog("L_INFO", "$sht(htable=>$var(carrier_key)::id) is not found\n");
    } else {
        xlog("L_INFO", "$sht(htable=>$var(carrier_key)::id) is found\n");
    };

and when the piece is executed, this is printed to syslog:

Oct 15 12:20:33 squeeze /usr/sbin/trunk-proxy[2915]: INFO: 0 is defined
Oct 15 12:20:33 squeeze /usr/sbin/trunk-proxy[2915]: INFO: 0 is not found

i understand the first line, because the entry is in the htable, but how
is it possible that string "0" is equal to int 0?

-- juha