js中使用數組的map和join函數實現日期格式化

來自微信小程序demo

var currDate = Date.now();
$("#currTime").text(formatTime(new Date(currDate)));//這是jq的賦值方式，不是重點

//重點在這，利用數組的map
function formatTime(date){
	const year = date.getFullYear();
	const month = date.getMonth() + 1;
	const day = date.getDate();
	const hour = date.getHours();
	const minute = date.getMinutes();
	const second = date.getSeconds();
	return [year, month, day].map(formatNumber).join('/') + ' ' + [hour, minute, second].map(formatNumber).join(':');
}
function formatNumber(n){
	n = n.toString()
	return n[1] ? n : '0' + n;
}