演示dump函数，这是最常用的工具哦
Array
(
    [title] => 静夜思
    [code] => Array
        (
            [one] => 床前明月光
            [two] => 疑是地上霜
            [three] => 举头望明月
            [four] => 低头思故乡
        )

    [author] => 李白
)

Array
(
)

Array
(
    [a] => dump
    [c] => other
)
请返回MainController/actionIndex