parseTime-时间格式化函数

parseTime(time, pattern) {
      if (arguments.length === 0 || !time) {
        console.warn("未传入正确的时间格式：new Date()!");
        return null;
      }
      const format = pattern || "{y}-{m}-{d} {h}:{i}:{s}";
      let date;
      if (typeof time === "object") {
        date = time;
      } else {
        if ((typeof time === "string") && (/^[0-9]+$/.test(time))) {
          time = parseInt(time);
        } else if (typeof time === "string") {
          time = time.replace(new RegExp(/-/gm), "/");
        }
        if ((typeof time === "number") && (time.toString().length === 10)) {
          time = time * 1000;
        }
        date = new Date(time);
      }
      const formatObj = {
        y: date.getFullYear(),
        m: date.getMonth() + 1,
        d: date.getDate(),
        h: date.getHours(),
        i: date.getMinutes(),
        s: date.getSeconds(),
        a: date.getDay()
      };
      return format.replace(/{(y|m|d|h|i|s|a)+}/g, (result, key) => {
        let value = formatObj[key];
        // Note: getDay() returns 0 on Sunday
        if (key === "a") {
          return ["日", "一", "二", "三", "四", "五", "六"][value];
        }
        if (result.length > 0 && value < 10) {
          value = "0" + value;
        }
        return value || 0;
      });
    }