判断某年某月有几天

getNumberDaysInMonth = function (inMonth,inYear) {
    inMonth = inMonth-1;
    var leap_year = this.isLeapYear(inYear);
    if (leap_year){
        leap_year =1;
    }else{
        leap_year = 0;
    }
    if(inMonth==3 ||inMonth==5 ||inMonth==8 ||inMonth==10){
        return 30;
    }else if(inMonth ==1){
        return 28+leap_year;
    }else{
        return 31;
    }
}
isLeapYear =function (inYear) {
    if((inYear%4 ==0&&!(inYear%100==0))||inYear%400==0){
        return true;
    }else{
　　
　　　　return false;
　　}
}
var days = getNumberDaysInMonth(2,2016);
console.log(days); //29