javascript - 如何使当前时间出现在警告框中

Question

如何使当前时间出现在警告框中？我是编程新手，所以我完全迷路了。我正在用 html5 或 javascript 编码。我已经在此处添加了大部分代码。

这是我的代码:

<script>
    function startTime(){
        var today=Date();
        var h=today.getHours();
        var m=today.getMinutes();
        var s=today.getSeconds(); 
        document.getElementById('txt').innerHTML=h+":"+m+":"+s; 
    }

</script>
<div id="txt"></div>

<h1>What would you like it to say?</h1>

    <p>Commmon Requests:</p>

    <form action="">
    <select name="requests" onchange ="checkIfOther();" id="dropDown1">
    <option value="blank"> </option>
    <option value="good morning sir">Good Morning Sir</option>
    <option value="current time">Current Time</option>
    <option value="other">Other</option>    
    </select>
    </form>

    </p>
<button onclick="mySubmit()" value>Submit</button>

    <div id="other" style="display:none">
        <br><br><label>Optional Request: </label><input type="text" id="otherText"/>
    </div>

</body>
</html>

<script>
    function checkIfOther(){
        a=document.getElementById("dropDown1");        
        if(a.value == "other"){           
            document.getElementById("other").setAttribute("style","display:inline");
        }
        else{
            document.getElementById("other").setAttribute("style","display:none");
            }
    }   
</script>

<script type="text/javascript">
    function mySubmit(){
        var x=document.getElementById("dropDown1");
        if(x.value == "other"){
            alert("You have chosen: " + otherText.value); 
        }
        else if(x.value == "current time"){
            alert("The current time is: " + 'txt'.value); //what do I do here?
        }
        else{   
            alert("You have chosen: " + x.options[x.selectedIndex].text);
        }   
    }   
</script>

我做错了什么吗？

Answer 1

首先，您的 HTML 完全搞砸了。验证它。

至于代码本身，startTime被打破。它需要 new Date() .

function startTime(){
  var today = new Date();
  var h = today.getHours();
  var m = today.getMinutes();
  var s = today.getSeconds(); 
  return [ h, m, s ].join(':')
}

要将其放入警告框，您只需执行以下操作:

alert(startTime());

如果你想把它放在像<div id="txt"></div> 这样的元素中你可以这样做:

document.getElementById('txt').innerHTML = startTime();