??var?score;?//score變量，用來存儲用戶輸入的成績值。????score?=?prompt("請輸入你的成績：")?;????if(score>=90)????{document.write("你很棒!");}????else?if(score>=75)????{document.write("不錯(cuò)吆!");? }????else?if(score>=60)????{document.write("要加油!");?}????else?if(score>=0)????{???????document.write("要努力了!");????}????else????{????document.write("請輸入成績！");????}? ?在我點(diǎn)擊”取消按鈕時(shí)“返回，要努力了，當(dāng)我把else?if(score>=0)改為else?if(score=0)返回請輸入成績不懂了?why ?why?
提問（prompt 消息對話框）
三月桃花雪
2015-10-14 20:45:39
