jQuery轮播图（模仿滑动窗口算法）

    const status = [
      "left:0px;",
      "left:10px;",
      "left:20px;",
      "left:30px;",
      "left:40px;",
    ];
    const list = $("#carousel > ul > li");
    const len = list.length;
    let pointer = 0;

    function change(dir) {
      pointer = outRange(dir ? ++pointer : --pointer);
      for (let i = 0, len = status.length; i < len; i++)
        $(list[outRange(pointer + i)]).attr("style", status[i]);
    }

    function outRange(val) {
      return val >= len ? 0 : val < 0 ? len - 1 : val;
    }

    $("#bu1").click(function () {
      change(true);
    });
    $("#bu2").click(function () {
      change(false);
    });

    ```