从php数组生成输出

Question

i'm trying to generate a firewall template from a php config

i've got this array

$config=array('1024','3306','3804','127017');

and i would like this output

1024:3305
3307:3803
3805:127017

as you can see, the first and last value stay the same, the value in between are -1 / +1

i think i can do it but not in a clean way, i tried to manipulate the array but in a wrong way i guess because the code is too verbose

may you help ?

thanks

Answer 1

$config=array('1024','3306','3804','127017');

$output = [];

foreach ($config as $k => $port) {
    if (isset($config[$k+1])) {
        $output[] = ($k ? $port + 1 : $port)
            . ':'
            . (isset($config[$k+2]) ? ($config[$k + 1] - 1) : $config[$k + 1]);
    }
}

echo implode("<br>", $output);