为什么这段代码的其他部分不运行？
[英]Why doesn't the else part of this code run?
问题描述
I don't know if I am missing something but there is something wrong with this code. 
我不知道我是否缺少某些内容，但是这段代码有问题。 When I leave the input area blank the else part should run, but it does not. 当我将输入区域留为空白时，else部分应该运行，但是不会运行。 Can someone explain me why? 有人可以解释我为什么吗？
<html>
<head>
<script type="text/javascript">
</script>
</head>
<body>
<p> Put your name and see what happens. </p>
<input id="nameinput">
<button onclick="myFunction()">Click To See Your Name</button>
<p id="namedemo"></p>
<script type="text/javascript">
function myFunction() {
if (document.getElementById("nameinput") != "") {
var u;
u = document.getElementById("nameinput").value;
document.getElementById("namedemo").innerHTML = "Your name is " + u;
}
else {
alert("Please fill required field");
}
}
</script>
</body>
</html>
1 个解决方案
解决方案1
3 已采纳 2017-01-10 15:26:51
You are missing the .value in your statement, It should be 您在语句中缺少.value ，应该是
if(document.getElementById("nameinput").value != ""){
Here is a working DEMO : https://jsfiddle.net/ku7ubhnL/ 这是一个有效的DEMO： https : //jsfiddle.net/ku7ubhnL/
Hope this helps! 希望这可以帮助！
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