var?years=prompt("請輸入您的出生年份");
var?months=prompt("請輸入您的出生月份");
var?days=prompt("請輸入您的出生日期");
//判斷用戶輸入格式
function?userText(){
????if(isNaN(years)?&&?isNaN(months)?&&?isNaN(days)){
????????alert("必須輸入數字");
????????return?false;
????}
????if(!(years&&months&&days)){
????????alert("不能為空");
????????return?false;
????}
????if(months<=0?||?months>12){
????????alert("請輸入正確的月份！");
????????return?false;
????}else{
????return?true;}
}
//判斷閏年
function?isLeapYear(){
????return?(years%4==0?&&?years%100!=0?||?years%400==0)
}
//?整理每個月的天數
var?monthDay=[31,28,31,30,31,30,31,31,30,31,30,31];
var?monthnub=parseInt(months);
function?numDay(){
????switch(parseInt(months)){
????????
????????case?1:
????????return?parseInt(days);
????????break;
????????case?2:
????????return?parseInt(days)+monthDay[0];
????????break;
??????????if(isLeapYear()){
??????????????monthDay[1]=29;
??????????}
????????case?3:
????????return?parseInt(days)+monthDay[0]+monthDay[1];
????????break;
????????case?4:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2];
????????break;
????????case?5:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3];
????????break;
????????case?6:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3]+monthDay[4];
????????break;
????????case?7:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3]+monthDay[4]+monthDay[5];
????????break;
????????case?8:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3]+monthDay[4]+monthDay[5]+monthDay[6];
????????break;
????????case?9:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3]+monthDay[4]+monthDay[5]+monthDay[6]+monthDay[7];
????????break;
????????case?10:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3]+monthDay[4]+monthDay[5]+monthDay[6]+monthDay[7]+monthDay[8];
????????break;
????????case?11:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3]+monthDay[4]+monthDay[5]+monthDay[6]+monthDay[7]+monthDay[8]+monthDay[9];
????????break;
????????case?12:
????????return?parseInt(days)+monthDay[0]+monthDay[1]+monthDay[2]+monthDay[3]+monthDay[4]+monthDay[5]+monthDay[6]+monthDay[7]+monthDay[8]+monthDay[9]+monthDay[10];
????????break;
????}
}
numDay();
isLeapYear();
userText();
document.write("你的生日是在"?+?years?+?"年的第"?+?numDay()+?"天");請問numDay()里面的函數該如何簡化，實在是js很新很新的新人。麻煩大牛修改一下，能讓我看得懂的方法
根據輸入的年、月、日，計算出出生那天是該年的第幾天
程序學習袁
2017-04-13 13:45:34
