获取当前月的天数

/** * @param {year} 当前的年份 * @param {month} 当前的月份 */ //获取这个月有多少天 export const getMonthDayNum = function (year = 2020,month = 1) { if(month < 1 || month > 12){ console.log("参数不合法") return } let num = 28; switch(month){ case 1: num = 31;break; //计算闰年的方式 case 2: if(year%4 == 0 || (year % 400 == 0 && year % 100 == 0)){ num = 29 }else{ num = 28 } ;break; case 3: num = 31;break; case 4: num = 30;break; case 5: num = 31;break; case 6: num = 30;break; case 7: num = 31;break; case 8: num = 31;break; case 9: num = 30;break; case 10: num = 31;break; case 11: num = 30;break; case 12: num = 31;break; default: num = 28;break; } return num;//默认就是28 }