swift计算 switch case

var year =
var month =
var day = ;
let daysOfFeb = year %  ==  && year%  !=  || year %  ==  ?:
var count =  // 定义一个变量 代表结果
switch month{
case :count += ; fallthrough
case :count += ; fallthrough
case :count += ; fallthrough
case :count += ; fallthrough
case :count += ; fallthrough
case :count += ; fallthrough
case :count += ; fallthrough
case :count += ; fallthrough
case :count += ; fallthrough
case :count += daysOfFeb; fallthrough
case :count += ; fallthrough
    case :count += day
default:break
}
print("\(year)年\(month)月\(day)日 是一年当中的第\(count)天")