js获取当前日期（年份，月份，时间）

获取当前日期（年份，月份，时间）：
function getDateTime (type) {
  var date = new Date();
  var hengGang = "-";
  var maoHao = ":";
  var year = date.getFullYear();
  var month = date.getMonth() + 1;
  var curDate = date.getDate();
  var curHours = date.getHours();
  var curMinutes = date.getMinutes();
  var curSeconds = date.getSeconds();

  if (month >= 1 && month <= 9) {
    month = "0" + month;
  }
  if (curDate >= 0 && curDate <= 9) {
    curDate = "0" + curDate;
  }
  if (curHours >= 0 && curHours <= 9) {
    curHours = "0" + curHours;
  }
  if (curMinutes >= 0 && curMinutes <= 9) {
    curMinutes = "0" + curMinutes;
  }
  if (curSeconds >= 0 && curSeconds <= 9) {
    curSeconds = "0" + curSeconds;
  }
  var currentdate = "";
  if (type == "year") {
    currentdate = year;
    return currentdate;
  } else if (type == "month") {
    currentdate = year + hengGang + month;
    return currentdate;
  } else {
    currentdate = year + hengGang + month + hengGang + curDate + " " + curHours + maoHao + curMinutes + maoHao + curSeconds;
    return currentdate;
  }
}
var year = getDateTime('year');  
console.log(year);  // 2021
var month = getDateTime('month');  
console.log(month); // 12
var date = getDateTime('');
console.log(date);  // 2021-12-03 09:00:00