将 if else 转换为 switch 语句答案

【问题标题】：converted if else to switch statements将 if else 转换为 switch 语句
【发布时间】：2017-12-11 08:09:10
【问题描述】：

这是我到目前为止创建的代码，但它不起作用。我只是一个初学者，我们正在创建这个“猜你的星座”代码作为我们学校的一项工作。

请帮我改一下代码的问题:((

另外（对不起，如果我要求太多东西）我怎样才能在每种情况下插入一张照片，比如每个星座都有一张照片？

<html>
<body>
  <h1> Guess your ZODIAC </h1>
  <script>


window.confirm("HELLO");
window.confirm("I will try to determine your ZODIAC SIGN via this html. Cooperate with me :) ?");
window.confirm("oki, lego");

var zodiacmonth = prompt("Please insert your birthMONTH; if your birthday is on January 11, insert January");
var zodiacday = prompt("Please insert birthDAY; if your birthday is on January 11, insert 11")

switch (sign) {
   case ((zodiacmonth == "February" && zodiacday >= 19) || (zodiacmonth == "March" && zodiacday <=20)): 
   window.confirm ("Your zodiac sign is PISCES");
   break;

   case ((zodiacmonth == "March" && zodiacday >= 21) || (zodiacmonth == "April" && zodiacday <=19)):
   window.confirm ("Your zodiac sign is ARIES");
   break;

   case ((zodiacmonth == "April" && zodiacday >= 20) || (zodiacmonth == "May" && zodiacday <=20)):
      window.confirm ("Your zodiac sign is TAURUS");
      break;

   case zodiacmonth == "May" && zodiacday >= 21 || zodiacmonth == "June" && zodiacday <=20 : 
      window.confirm ("Your zodiac sign is GEMINI");
      break;

   case zodiacmonth == "June" && zodiacday >= 21 || zodiacmonth == "July" && zodiacday <=22:
      window.confirm ("Your zodiac sign is CANCER");
      break;

   case zodiacmonth == "July" && zodiacday >= 23 || zodiacmonth == "August" && zodiacday <=22 :
      window.confirm ("Your zodiac sign is LEO");
      break;

   case zodiacmonth == "August" && zodiacday >= 23 || zodiacmonth == "September" && zodiacday <=22: 
      window.confirm ("Your zodiac sign is VIRGO");
      break;

   case zodiacmonth == "September" && zodiacday >= 23 || zodiacmonth == "October" && zodiacday <=22: 
      window.confirm ("Your zodiac sign is LIBRA");
      break;

   case zodiacmonth == "October" && zodiacday >= 23 || zodiacmonth == "November" && zodiacday <=21:  
      window.confirm ("Your zodiac sign is SCORPIO");
      break;

   case zodiacmonth == "November" && zodiacday >= 22 || zodiacmonth == "December" && zodiacday <=21:  
      window.confirm ("Your zodiac sign is SAGITTARIUS");

   case  zodiacmonth == "December" && zodiacday >= 22 || zodiacmonth == "January" && zodiacday <=19: 
      window.confirm ("Your zodiac sign is CAPRICORN");
      break;

  case  zodiacmonth == "January" && zodiacday >= 20 || zodiacmonth == "February" && zodiacday <=18: 
        window.confirm ("Your zodiac sign is AQUARIUS, like mine :))");
      break;



   } 

  </script>
  </body>
</html>

【问题讨论】：

您不能与switch...case 语句进行比较。你必须继续使用ifs
改用switch (true) { - 因为sign 没有在任何地方声明，你认为它是什么？
我建议你在case语句中也一直使用()，不知道为什么你在taurus之后停止

标签： javascript image if-statement switch-statement photo

【解决方案1】：

case 与 if(/else) 语句不同。

switch/case 块可用于检查单个变量的不同值。

您的条件包括多个变量，因此这里甚至不可能使用 switch/case 块（/实用）。

也就是说，如果您更好地构建数据，则此代码可以优化：

var zodiacs = [
  { sign: "PISCES", monthA: "February", monthB: "March", dayA: 19, dayB: 20 },
  { sign: "ARIES", monthA: "March", monthB: "April", dayA: 21, dayB: 19 },
  { sign: "TAURUS", monthA: "April", monthB: "May", dayA: 20, dayB: 20 },
  // etc
];

var zodiacmonth = prompt("Please insert your birthMONTH; if your birthday is on January 11, insert January");
var zodiacday = prompt("Please insert birthDAY; if your birthday is on January 11, insert 11")

var zodiac = zodiacs.filter(function(z){
  return zodiacmonth == z.monthA && zodiacday >= z.dayA ||
    zodiacmonth == z.monthB && zodiacday <= z.dayB;
})[0]

console.log(zodiac);

window.confirm ("Your zodiac sign is " + zodiac.sign);

让月份比较不区分大小写也很有用：

zodiacmonth = zodiacmonth.toLowercase();
// and
{ sign: "PISCES", monthA: "february", monthB: "march", dayA: 19, dayB: 20 },   
//                         ^                   ^

【讨论】：