格式化日期

1、方法

const formatDate = (date, format = "YYYY-MM-DD HH:mm:ss") => {
  if (!date) {
    return "";
  }
  const d = new Date(date);
  // 年
  if (/YYYY/.test(format)) {
    format = format.replace(/YYYY/, d.getFullYear());
  }
  // 月份
  const month = d.getMonth() + 1;
  if (/MM/.test(format)) {
    const monthStr = month < 10 ? "0" + month : month;
    format = format.replace(/MM/, monthStr);
  } else if (/M/.test(format)) {
    format = format.replace(/M/, month);
  }
  // 日期
  const dates = d.getDate();
  if (/DD/.test(format)) {
    const dateStr = dates < 10 ? "0" + dates : dates;
    format = format.replace(/DD/, dateStr);
  } else if (/D/.test(format)) {
    format = format.replace(/D/, dates);
  }
  // 小时
  const hours = d.getHours();
  if (/HH/.test(format)) {
    const hoursStr = hours < 10 ? "0" + hours : hours;
    format = format.replace(/HH/, hoursStr);
  } else if (/H/.test(format)) {
    format = format.replace(/H/, hours);
  } else if (/hh/.test(format)) {
    const hoursMin = hours > 12 ? hours - 12 : hours;
    const hoursStr = hoursMin < 10 ? "0" + hoursMin : hoursMin;
    format = format.replace(/hh/, hoursStr);
  } else if (/h/.test(format)) {
    const hoursMin = hours > 12 ? hours - 12 : hours;
    format = format.replace(/h/, hoursMin);
  }
  // 分
  const minutes = d.getMinutes();
  if (/mm/.test(format)) {
    const minutesStr = minutes < 10 ? "0" + minutes : minutes;
    format = format.replace(/mm/, minutesStr);
  } else if (/m/.test(format)) {
    format = format.replace(/m/, minutes);
  }
  // 秒
  const seconds = d.getSeconds();
  if (/ss/.test(format)) {
    const secondsStr = seconds < 10 ? "0" + seconds : seconds;
    format = format.replace(/ss/, secondsStr);
  } else if (/s/.test(format)) {
    format = format.replace(/s/, seconds);
  }
  return format;
};

2、用法