implode 数组转换为字符串
$array = array('lastname', 'email', 'phone');
$comma_separated = implode(",", $array);
echo $comma_separated; // lastname,email,phone
explode 字符串转换为数组
$pizza = "piece1 piece2 piece3 piece4 piece5 piece6";
$pieces = explode(" ", $pizza);
echo $pieces[0];
echo $pieces[1];
$data = "foo:*:1023:1000::/home/foo:/bin/sh";...