Javascript处理日期显示问题

Web开发人员经常使用JavaScript来完成他们网站上的常见任务。在本教程中，我们将向您展示通过剪切和粘贴即可在网页上使用的前10个JavaScript片段！ 在本文中，我们将介绍以下流行的脚本片段

<SCRIPT LANGUAGE="JavaScript">
var now = new Date();

var days = new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');

var months = new Array('January','February','March','April','May','June','July','August','September','October','November','December');

var date = ((now.getDate()<10) ? "0" : "")+ now.getDate();

function fourdigits(number) {
    return (number < 1000) ? number + 1900 : number;
                                }
today =  days[now.getDay()] + ", " +
         months[now.getMonth()] + " " +
         date + ", " +
         (fourdigits(now.getYear())) ;

document.write(today);
</script>

var now=新日期（）；
var days=新数组（“星期日”、“星期一”、“星期二”、“星期三”、“星期四”、“星期五”、“星期六”）；
var months=新数组（“一月”、“二月”、“三月”、“四月”、“五月”、“六月”、“七月”、“八月”、“九月”、“十月”、“十一月”、“十二月”）；
var date=（（now.getDate（）在这两个函数中，您都需要计算下一个位置，因此我将其分为一个函数：

applyInstuction : Char -> Location -> Location
applyInstuction instruction loc =
    case instruction of
        '>' ->
            { loc | x = loc.x + 1 }

        '^' ->
            { loc | y = loc.y + 1 }

        '<' ->
            { loc | x = loc.x - 1 }

        'v' ->
            { loc | y = loc.y - 1 }

        _ ->
            loc

如果您不熟悉
foldl
（还有
foldr
）-您可以在这里查看它，例如：。它类似于JavaScript中的
map reduce

calculateFirstIntersection
接下来，我们可以使用
Set
（）实现
calculateFirstIntersection
。Set将存储我们已经访问过的位置。
代码如下：

calculateFirstIntersection : String -> Maybe Location
calculateFirstIntersection instructions =
    .result <|
        List.foldl
            (\instruction { visited, loc, result } ->
                case result of
                    Nothing ->
                        let
                            nextVisited =
                                Set.insert ( loc.x, loc.y ) visited

                            nextLoc =
                                applyInstuction instruction loc
                        in
                            if Set.member ( loc.x, loc.y ) visited then
                                { visited = nextVisited
                                , loc = nextLoc
                                , result = Just loc
                                }
                            else
                                { visited = nextVisited
                                , loc = nextLoc
                                , result = Nothing
                                }

                    _ ->
                        { visited = visited
                        , loc = loc
                        , result = result
                        }
            )
            { visited = Set.empty, loc = { x = 0, y = 0 }, result = Nothing }
        <|
            String.toList instructions

calculateFirstIntersection:String->Maybe Location
calculateFirstIntersection指令=
.结果
案例结果
没有->
让
下一次访问=
设置插入（位置x、位置y）已访问
下一个=
应用指令loc
在里面
如果访问了Set.EMBER（位置x、位置y），则
{visted=nextvisted
，loc=nextLoc
，结果=仅限loc
}
其他的
{visted=nextvisted
，loc=nextLoc
，结果=无
}
_ ->
{visted=visted
，loc=loc
，result=结果
}
)
{visted=Set.empty，loc={x=0，y=0}，result=Nothing}
不要诋毁帖子，即使是你创建的帖子。
calculateFirstIntersection : String -> Maybe Location
calculateFirstIntersection instructions =
    .result <|
        List.foldl
            (\instruction { visited, loc, result } ->
                case result of
                    Nothing ->
                        let
                            nextVisited =
                                Set.insert ( loc.x, loc.y ) visited

                            nextLoc =
                                applyInstuction instruction loc
                        in
                            if Set.member ( loc.x, loc.y ) visited then
                                { visited = nextVisited
                                , loc = nextLoc
                                , result = Just loc
                                }
                            else
                                { visited = nextVisited
                                , loc = nextLoc
                                , result = Nothing
                                }

                    _ ->
                        { visited = visited
                        , loc = loc
                        , result = result
                        }
            )
            { visited = Set.empty, loc = { x = 0, y = 0 }, result = Nothing }
        <|
            String.toList instructions