js获取当前日期（年份，月份，时间）

js获取当前日期（年份，月份，时间），实现方法：

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); // 2021-12
var date = getDateTime('');
console.log(date);  // 2021-12-03 09:00:00