数组转字符串
implode
$array = array('lastname', 'email', 'phone');
$comma_separated
= implode(
","
,
$array
);
字符串转数组
explode
$pizza
=
"piece1 piece2 piece3 piece4 piece5 piece6"
;
$pieces
=
explode
(
" "
,
$pizza
);