js--笔记(计算某月的天数)

 返回某年某月的天数

function getDays(year,month) {
  var days = 30
 
  if (month == "2")
   days = 28
  
  if ( (",1,3,5,7,8,10,12,").indexOf(","+month+",") > -1 )
   days = 31
  
  if (month == "2" && parseInt(year) % 4 ==0 && !(parseInt(year) % 100 == 0 && !(parseInt(year) % 400 == 0)))
   days = 29
  
  return days
 }