Question

我是初学程序员，我想做这项工作，但事实并非如此。你能帮我解释一下是什么问题吗？例如，如果我输入20岁以下，我希望它能告诉我走多长时间走到我选择的任何星球。其中大部分是弄清楚如何让代码存储用户选择的任何选项，然后将其应用于年龄并使用数据来计算它。谢谢！

<legend>basic info</legend>
    <p> What is your destination?
        <select onchange = "selectDestination(this.value)">
        <option value="mercury">Mercury</option>
        <option value="venus">Venus</option>
        <option value="mars">Mars</option>
        <option value="jupiter">Jupiter</option>
        <option value="saturn">Saturn</option>
        <option value="uranus">Uranus</option>
        <option value="neptune">Neptune</option>
        <option value="pluto">Pluto</option>
        </select>
        <script type="text/javascript">
          var planets = new Array();
         planets['mercury'] = 48000000;
         planets['venus']=25000000
         planets['mars']=25000000
         planets['jupiter']=33900000
         planets['saturn']=365000000
         planets['uranus']=1200000000
         planets['neptune']=2600000000
         planets['pluto']=2800000000

         function selectDestination(selectedValue) {
         window.alert(selectedValue + " distance=" + planets[selectedValue]);
        }          
        </script>
    </p>
    <p>
    <label>how old are you?</label> 
     <form id="form" onsubmit="return false;">
      <input type="number" id="userInput">
      <input type="submit"    onclick="age()">
     </form>
    <script type="text/javascript">
      function age()
      {
        var input = document.getElementById("userInput");
        alert(input);
      }
      if(age<20);
      {
      alert("YOU ARE UNDER 20");
      var runSpeed=6.3;
      var walkSpeed=2.1
      var water = 1.5;
      var calories = 2500;
      var runTime = planets[selectedValue]/runSpeed;
      var runDays = runTime/24
      document.write("it will take "+runTime+" hours and "+runDays+" days to make it to"+selectedValue);
      }
      if(21<age>45) {
      alert("YOU ARE AT YOUR PHYSICAL PEAK");
      var runSpeed=8.3;
      var walkSpeed=3.1;
      var water = 2;
      var calories = 3000;
      var runTime = planets[selectedValue]/runSpeed;
      var runDays = runTime/24;
      document.write("it will take "+runTime"hours and"+runDays+"days to make it to"+selectedValue);
      }
      if(age<45){
        alert("YOU ARE PROBABLY TOO OLD TO TAKE THIS TRIP");
        var runSpeed=5.3;
        var walkSpeed=1.1;
        var water=1.5;
        var calories=3000;
        var runTime = planets[selectedValue]/runSpeed;
        var rundays = planets[selectedValue]/24;
        document.write("it will take "+runTime"hours and"+runDays+"days to make it to"+selectedValue);
      }
    </script>
    </p>

Answer 1

此处的代码不起作用。

      var planets = new Array();
     planets['mercury'] = 48000000;
     planets['venus']=25000000
     planets['mars']=25000000
     planets['jupiter']=33900000
     planets['saturn']=365000000
     planets['uranus']=1200000000
     planets['neptune']=2600000000
     planets['pluto']=2800000000

您要声明的是一个数组，您想要推送的是对象。

你最理想的行星是var planets = [ {planet: 'mercury', distance: 48000000}, {planet: 'venus', distance: 25000000 }, ... ]

现在，没有任何事情发生，因为你的语法正在寻找一个密钥为mercury或venus而没有找到任何东西的对象。

接下来你要做的就是console.log()无论用户输入什么年龄。确保您的函数age()接受参数，因此它看起来更像age(val)

一旦您console.log()记录了用户输入的年龄，您应该非常接近。在此之后你所要做的就是抓住用户选择的行星，你可以通过循环遍历planets数组并将用户选择的内容与数组中的内容进行匹配来实现。像planets.filter(planet => planet.indexOf(planetUserSelected) !== -1)这样的东西可以让你找回你正在寻找的对象，你可以console.log()那个价值并从那里开始。

如何使用html和javascript制作一种计算器？

1 个答案: