03-输出某年某月某日的天数（精简）

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8 <script>
 9 
10     console.log(getDays(2015,3,1));
11     function getDays(year,month,day){
12         var arr = [31,28,31,30,31,30,31,31,30,31,30,31];
13         for(var i=0;i<month-1;i++){
14             day += arr[i];
15         }
16         if(month>2 && isRN(year)){
17             day+=1;
18         }
19         return day;
20     }
21     function isRN(year){
22         if(year%4===0 && year%100!==0 || year%400===0){
23             return true;
24         }
25         return false;
26     }
27 
28 
29 
30 </script>
31 </body>
32 </html>